Unit 2: Two-Dimensional Geometry
Scale Factor
Study.com - What is Scale Factor?
https://study.com/academy/lesson/what-is-a-scale-factor-definition-formula-examples.html
Khan Academy - Identifying Scale Factors
https://www.khanacademy.org/math/cc-seventh-grade-math/cc-7th-geometry/cc-7th-scale-drawings/v/identifying-scale-factors
Virtual Nerd - How Do You Find a Scale Factor
http://virtualnerd.com/geometry/similarity/polygons/find-scale-factor-similar-figures
Scale Factor Applications
Virtual Nerd - How Do You Solve A Scale Model Problem Using a Scale Factor
http://virtualnerd.com/geometry/similarity/ratios-proportions/scale-model-scale-factor
IXL - Scale Drawings: Word Problems
https://www.ixl.com/math/grade-7/scale-drawings-word-problems
https://www.ixl.com/math/grade-8/scale-drawings-word-problems
Triangles
Math is Fun - Definition of Acute Triangle
https://www.mathsisfun.com/definitions/acute-triangle.html
Math is Fun - Definition of Obtuse Triangle
https://www.mathsisfun.com/definitions/obtuse-triangle.html
Math is Fun - Definition of Right-Angled Triangle
https://www.mathsisfun.com/definitions/right-angled-triangle.html
Virtual Nerd - What are Acute, Obtuse and Right Triangles?
http://virtualnerd.com/pre-algebra/geometry/triangles/define-triangles/triangle-acute-obtuse-right-definition
HomeschoolMath.net - Acute, Obtuse, and Right Triangles
https://www.homeschoolmath.net/teaching/g/triangles.php
Khan Academy - Classifying Triangles Video
https://www.khanacademy.org/math/basic-geo/basic-geometry-shapes/basic-geo-classifying-triangles/v/scalene-isosceles-equilateral-acute-right-obtuse
CoolMath.com - Types of Triangles
http://www.coolmath.com/reference/triangles-types
Brightstorm Geometry - Triangle Angle Sum (watch up to the 1:40 mark)
https://www.brightstorm.com/math/geometry/triangles/triangle-angle-sum/
IXL Practice - Triangle Angle-Sum Theroem
https://www.ixl.com/math/geometry/triangle-angle-sum-theorem
Khan Academy - Angles in a Triangle Sum to 180 degrees Practice
https://www.khanacademy.org/math/basic-geo/basic-geometry-shapes/triangle-angles/e/triangle_angles_1
Angle Pairs
Math is Fun - Adjacent Angles
https://www.mathsisfun.com/geometry/adjacent-angles.html
Math is Fun - Vertical Angles
https://www.mathsisfun.com/geometry/vertical-angles.html
Khan Academy - Vertical Angles Video
https://www.khanacademy.org/math/basic-geo/basic-geo-angle/vert-comp-supp-angles/v/angles-at-the-intersection-of-two-lines
Virtual Nerd - What are Vertical Angles?
http://virtualnerd.com/geometry/fundamentals/angle-pair-relationships/vertical-angles-definition
Varsity Tutors - Linear Pair
https://www.varsitytutors.com/hotmath/hotmath_help/topics/linear-pair
Khan Academy - Angle Relationships
https://www.khanacademy.org/math/geometry-home/geometry-angles/geometry-vert-comp-supp/v/vertical-adjacent-and-linearly-paired-angles
Math is Fun - Complementary Angles
https://www.mathsisfun.com/geometry/complementary-angles.html
Virtual Nerd - What are Complementary Angles?
http://virtualnerd.com/middle-math/geometric-figures/angles/complementary-angles-definition
Khan Academy - Complementary and Supplementary Angles
https://www.khanacademy.org/math/basic-geo/basic-geo-angle/vert-comp-supp-angles/v/complementary-and-supplementary-angles
Math is Fun - Supplementary Angles
https://www.mathsisfun.com/geometry/supplementary-angles.html
Virtual Nerd - What are Supplementary Angles?
http://virtualnerd.com/middle-math/geometric-figures/angles/supplementary-angles-definition
Circles
Math is Fun - Circle
https://www.mathsisfun.com/geometry/circle.html
Khan Academy - Radius, Diameter, Circumference
https://www.khanacademy.org/math/basic-geo/basic-geo-area-and-perimeter/area-circumference-circle/v/circles-radius-diameter-and-circumference
Khan Academy - Labeling Parts of a Circle
https://www.khanacademy.org/math/basic-geo/basic-geo-area-and-perimeter/area-circumference-circle/v/parts-of-a-circle
Math Open Reference - Radius of a Circle
https://www.mathopenref.com/radius.html
Math Open Reference - Diameter of a Circle
https://www.mathopenref.com/diameter.html
Circumference
Math Open Reference - Circumference
https://www.mathopenref.com/circumference.html
Khan Academy - Radius, Diameter, Circumference
https://www.khanacademy.org/math/basic-geo/basic-geo-area-and-perimeter/area-circumference-circle/v/circles-radius-diameter-and-circumference
Virtual Nerd - What is Circumference?
http://virtualnerd.com/pre-algebra/perimeter-area-volume/circles/circumference/circlue-circumference-formula
Math Planet - Calculating the Circumference
https://www.mathplanet.com/education/pre-algebra/more-about-equation-and-inequalities/calculating-the-circumference-of-a-circle
Brightstorm - Circumference
https://www.brightstorm.com/math/geometry/circles/circumference/
Algebra4children - Find the Circumference of a Circle Memory Game
http://algebra4children.com/Games/Circumference/Circumference.html
Area of a Circle
Khan Academy - Area of a Circle
https://www.khanacademy.org/math/basic-geo/basic-geo-area-and-perimeter/area-circumference-circle/v/area-of-a-circle
Math is Fun - Area of a Circle
https://www.mathsisfun.com/geometry/circle-area.html
Virtual Nerd - How Do You Find the Area of a Circle if You Know the Diameter?
http://virtualnerd.com/geometry/length-area/circles-sectors-area/circle-area-from-diameter
Math Goodies - Area of a Circle
https://www.mathgoodies.com/lessons/vol2/circle_area
AAA - Area of a Circle Practice
http://www.aaamath.com/geo612x2.htm
Flocabulary - Circles: Circumference and Area
https://www.flocabulary.com/unit/circles/
IXL - Area and Circumference
https://www.ixl.com/math/geometry/area-and-circumference-of-circles
Area of Partial Circles
TutorVista.com - Area of a Semicircle
https://math.tutorvista.com/geometry/area-of-a-semicircle.html
Math Open Reference - Semicircle
https://www.mathopenref.com/semicircle.html
IXL - Semicircles
https://www.ixl.com/math/grade-7/semicircles-calculate-area-perimeter-radius-and-diameter
OnlineMath4All - Semicircle
https://www.onlinemath4all.com/semicircle.html
IXL - Quarter Circles
https://www.ixl.com/math/grade-7/quarter-circles-calculate-area-perimeter-and-radius
Study.com - What is Scale Factor?
https://study.com/academy/lesson/what-is-a-scale-factor-definition-formula-examples.html
Khan Academy - Identifying Scale Factors
https://www.khanacademy.org/math/cc-seventh-grade-math/cc-7th-geometry/cc-7th-scale-drawings/v/identifying-scale-factors
Virtual Nerd - How Do You Find a Scale Factor
http://virtualnerd.com/geometry/similarity/polygons/find-scale-factor-similar-figures
Scale Factor Applications
Virtual Nerd - How Do You Solve A Scale Model Problem Using a Scale Factor
http://virtualnerd.com/geometry/similarity/ratios-proportions/scale-model-scale-factor
IXL - Scale Drawings: Word Problems
https://www.ixl.com/math/grade-7/scale-drawings-word-problems
https://www.ixl.com/math/grade-8/scale-drawings-word-problems
Triangles
Math is Fun - Definition of Acute Triangle
https://www.mathsisfun.com/definitions/acute-triangle.html
Math is Fun - Definition of Obtuse Triangle
https://www.mathsisfun.com/definitions/obtuse-triangle.html
Math is Fun - Definition of Right-Angled Triangle
https://www.mathsisfun.com/definitions/right-angled-triangle.html
Virtual Nerd - What are Acute, Obtuse and Right Triangles?
http://virtualnerd.com/pre-algebra/geometry/triangles/define-triangles/triangle-acute-obtuse-right-definition
HomeschoolMath.net - Acute, Obtuse, and Right Triangles
https://www.homeschoolmath.net/teaching/g/triangles.php
Khan Academy - Classifying Triangles Video
https://www.khanacademy.org/math/basic-geo/basic-geometry-shapes/basic-geo-classifying-triangles/v/scalene-isosceles-equilateral-acute-right-obtuse
CoolMath.com - Types of Triangles
http://www.coolmath.com/reference/triangles-types
Brightstorm Geometry - Triangle Angle Sum (watch up to the 1:40 mark)
https://www.brightstorm.com/math/geometry/triangles/triangle-angle-sum/
IXL Practice - Triangle Angle-Sum Theroem
https://www.ixl.com/math/geometry/triangle-angle-sum-theorem
Khan Academy - Angles in a Triangle Sum to 180 degrees Practice
https://www.khanacademy.org/math/basic-geo/basic-geometry-shapes/triangle-angles/e/triangle_angles_1
Angle Pairs
Math is Fun - Adjacent Angles
https://www.mathsisfun.com/geometry/adjacent-angles.html
Math is Fun - Vertical Angles
https://www.mathsisfun.com/geometry/vertical-angles.html
Khan Academy - Vertical Angles Video
https://www.khanacademy.org/math/basic-geo/basic-geo-angle/vert-comp-supp-angles/v/angles-at-the-intersection-of-two-lines
Virtual Nerd - What are Vertical Angles?
http://virtualnerd.com/geometry/fundamentals/angle-pair-relationships/vertical-angles-definition
Varsity Tutors - Linear Pair
https://www.varsitytutors.com/hotmath/hotmath_help/topics/linear-pair
Khan Academy - Angle Relationships
https://www.khanacademy.org/math/geometry-home/geometry-angles/geometry-vert-comp-supp/v/vertical-adjacent-and-linearly-paired-angles
Math is Fun - Complementary Angles
https://www.mathsisfun.com/geometry/complementary-angles.html
Virtual Nerd - What are Complementary Angles?
http://virtualnerd.com/middle-math/geometric-figures/angles/complementary-angles-definition
Khan Academy - Complementary and Supplementary Angles
https://www.khanacademy.org/math/basic-geo/basic-geo-angle/vert-comp-supp-angles/v/complementary-and-supplementary-angles
Math is Fun - Supplementary Angles
https://www.mathsisfun.com/geometry/supplementary-angles.html
Virtual Nerd - What are Supplementary Angles?
http://virtualnerd.com/middle-math/geometric-figures/angles/supplementary-angles-definition
Circles
Math is Fun - Circle
https://www.mathsisfun.com/geometry/circle.html
Khan Academy - Radius, Diameter, Circumference
https://www.khanacademy.org/math/basic-geo/basic-geo-area-and-perimeter/area-circumference-circle/v/circles-radius-diameter-and-circumference
Khan Academy - Labeling Parts of a Circle
https://www.khanacademy.org/math/basic-geo/basic-geo-area-and-perimeter/area-circumference-circle/v/parts-of-a-circle
Math Open Reference - Radius of a Circle
https://www.mathopenref.com/radius.html
Math Open Reference - Diameter of a Circle
https://www.mathopenref.com/diameter.html
Circumference
Math Open Reference - Circumference
https://www.mathopenref.com/circumference.html
Khan Academy - Radius, Diameter, Circumference
https://www.khanacademy.org/math/basic-geo/basic-geo-area-and-perimeter/area-circumference-circle/v/circles-radius-diameter-and-circumference
Virtual Nerd - What is Circumference?
http://virtualnerd.com/pre-algebra/perimeter-area-volume/circles/circumference/circlue-circumference-formula
Math Planet - Calculating the Circumference
https://www.mathplanet.com/education/pre-algebra/more-about-equation-and-inequalities/calculating-the-circumference-of-a-circle
Brightstorm - Circumference
https://www.brightstorm.com/math/geometry/circles/circumference/
Algebra4children - Find the Circumference of a Circle Memory Game
http://algebra4children.com/Games/Circumference/Circumference.html
Area of a Circle
Khan Academy - Area of a Circle
https://www.khanacademy.org/math/basic-geo/basic-geo-area-and-perimeter/area-circumference-circle/v/area-of-a-circle
Math is Fun - Area of a Circle
https://www.mathsisfun.com/geometry/circle-area.html
Virtual Nerd - How Do You Find the Area of a Circle if You Know the Diameter?
http://virtualnerd.com/geometry/length-area/circles-sectors-area/circle-area-from-diameter
Math Goodies - Area of a Circle
https://www.mathgoodies.com/lessons/vol2/circle_area
AAA - Area of a Circle Practice
http://www.aaamath.com/geo612x2.htm
Flocabulary - Circles: Circumference and Area
https://www.flocabulary.com/unit/circles/
IXL - Area and Circumference
https://www.ixl.com/math/geometry/area-and-circumference-of-circles
Area of Partial Circles
TutorVista.com - Area of a Semicircle
https://math.tutorvista.com/geometry/area-of-a-semicircle.html
Math Open Reference - Semicircle
https://www.mathopenref.com/semicircle.html
IXL - Semicircles
https://www.ixl.com/math/grade-7/semicircles-calculate-area-perimeter-radius-and-diameter
OnlineMath4All - Semicircle
https://www.onlinemath4all.com/semicircle.html
IXL - Quarter Circles
https://www.ixl.com/math/grade-7/quarter-circles-calculate-area-perimeter-and-radius