Angles
Types of Triangles
Lines
Quadrilaterals
Properties of triangles
100
A pair of angles whose sum is 90 degrees
What are complementary angles?
100
A triangle in which one angle measures more than 90 degrees
What is an obtuse triangle?
100
Two lines that intersect to form right angles
What are perpendicular lines?
100
A quadrilateral with only one pair of parallel sides; they are called the bases (b1 and b2)
What is a trapezoid?
100
All angles in a triangle add to 180 degrees

What is the triangle sum theorem?

200
A pair of angles whose sum is 180 degrees
What are supplementary angles?
200
A triangle in which all three angles are less than 90 degrees
What is an acute triangle?
200
Two or more lines that never intersect
What are parallel lines?
200
A quadrilateral with two pairs of parallel sides
What is a parallelogram?
200
Two angles that are far away from the outside angle

What are remote interior angles?

300
A pair of adjacent angles whose non-common sides are opposite rays; a pair of adjacent angles that form a straight line
What is a linear pair?
300
A triangle in which one angle measures exactly 90 degrees
What is a right triangle?
300
A line that intersects two or more parallel lines
What is a transversal?
300
A parallelogram with four right angles
What is a rectangle?
300

The outside angle is equal to the sum of the remote interior angle.

What is the exterior angle theorem?

400
A pair of angles that share a common ray and vertex; a pair of angles that are "next to" each other
What are adjacent angles?
400
A triangle with two or more congruent sides
What is an isosceles triangle?
400
Pairs of angles that lie between parallel lines and on opposite sides of the transversal
What are alternate interior angles?
400
A parallelogram with 4 congruent sides
What is a rhombus?
400

The sum of the two smaller sides must be larger than the third

What is triangle inequality theorem?

500
A pair of angles who share a vertex and are "across from" or "opposite" each other
What are vertical angles?
500
A triangle with three congruent sides and three congruent angles; also known as a "regular" triangle
What is an equilateral (or equiangular) triangle?
500
Angle pairs that lie in the "same location" when a transversal intersects parallel lines
What are corresponding angles?
500
A parallelogram with four congruent sides and four right angles; also known as a "regular" quadrilateral
What is a square?
500

The largest side is across from the largest angle

What is the relationship between sides and angles?

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