Triangle Similarity

Ratio

A comparison of two numbers or measurements

Proportion

A ratio that compares different units (ex: miles per hour)

Dilation

A transformation that changes the size of an object, but not the shape

Equilateral Triangle

A triangle with 3 congruent sides and 3 congruent angles.

Acute Triangle

A triangle with all 3 angles less than 90 degrees.

Scalene Triangle

A triangle with no congruent sides.

Obtuse Triangle

A triangle with one angle larger than 90 degrees.

Isosceles Triangle

A triangle with one pair of congruent sides and one pair of congruent angles.

Right angles congruence theorem

All right angles are congruent

AA Similarity

If a pair of triangles have 2 pairs of congruent angles, then the triangles are similar.

3-side Proportionality Similarity

If a pair of triangles have 3 pairs of proportional sides, then the triangles are similar.

Similar Figures

Shapes with congruent angles and proportional sides

Transformation

The movement of a geometric figure

Scale Factor

The whole number or fraction used to multiply the sides of a shape to make a similar image.

Cross Multiply

Use to solve a proportion

Vertical angles theorem

Vertical angles are congruent