Triangle Similarity

Ratio

A comparison of two numbers or measurements

Proportion

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

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.

SSS Similarity

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

SAS Similarity

If a pair of triangles have two pairs of proportional sides and the angle between them is congruent, then the triangles are similar

Parallel

Lines are parallel if they have the same slope.

Perpendicular

Lines that intersect and form 90 degree angles.

Similar Figures

Shapes with congruent angles and proportional sides

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