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Unit 4: Geometry

Vocabulary for Unit 4

Acute Angle An angle that measures less than 90 degrees.
Right Angle An angle that measures exactly 90 degrees.
Obtuse Angle An angle that measures more than 90 degrees.
Equilateral A triangle with all equal sides.
Scalene A triangle with no equal sides.
Isosceles A triangle with two equal sides.
Complementary Angles The sum of two or more angles that equal exactly 90 degrees.
Supplementary Angles The sum of two or more angles that equal exactly 180 degrees.
Vertical Angles A pair of angles that are on opposite sides of a vertex and are always equal.
The sum of all angles in a triangle will always equal? 180 degrees
Triangle Inequality Theorem The two shortest side lengths of a triangle must have a sum greater than the longest side length of a triangle.
Area of a Rectangle/Square A = length x width
Area of a Parallelogram A = base x height
Area of a Circle A = pi x radius squared
Area of a Trapezoid A = one half times height times the sum of base 1 and base 2
Area of a Triangle A = one half times base times height
Volume Formula V = area of the base times height
Radius The length from the origin of a circle to the perimeter
Diameter The length through a circle that passes through the origin
Circumference The distance around a circle
What is 2D? 2- dimensional, a flat shape, no depth
What is 3D? 3-dimensional
Define area. Area covers the surface or face
Define volume. Volume fills a 3D object
Characteristics of a Prism Prisms are 3D shapes that always have two equal, parallel bases
Characteristics of a Pyramid Pyramids are 3D shapes that have one base opposite of the vertex
Face A face of a 3D shape is a flat surface
Vertex Where 3 or more edges intersect
Edge Where two faces intersect
Origin Center of a circle
Surface Area The measurement to cover all the faces of a 3D object
Created by: missgellinck
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