Congruent Angles

Congruent Triangles

Review​

By Daniela Funez

Congruence

Congruence is when there are two identical shapes, and in this lesson triangles, that are the same because their size, angles, and side lengths were preserved after a rigid motion.

Mathematics | Geometry

1

Multiple Choice

Are the two triangles congruent?

• Yes

• No

Multiple Choice

Which two triangles are congruent?

• ABC & DEF

• ABC & GHI

• ABC & JKL

• DEF & JKL

Corresponding Angles & Sides

2

Side-Side-Side: ​all sides to a shape are identical and prove two shapes are congruent

Side-Angle-Side: ​a pair of corresponding sides, a pair of congruent angles & a pair of corresponding sides in that order.

Angle-Side-Angle: ​ ​a pair of corresponding angles, a pair of congruent sides & a pair of corresponding angles

Angle-Angle-Side: ​two pairs of corresponding angles, & a pair of corresponding sides

​Congruence Theorem

Translation - the shape slides in one direction either left & right or up & down.

Rotation - ​the shape moves around any certain point

Reflection​ - the shape is mirrored across an axis or line segment

​Rigid Motions

Multiple Choice

Which congruence theorem proves these two triangles are congruent?

• SSS Theorem

• SAS Theorem

• ASA Theorem

• AAS Theorem

Open Ended

Which congruence theorem can be used to identify congruency and why?

Multiple Choice

What rigid motion is represented in the graph?

• Translation

• Rotation

• Reflection

Multiple Choice

What rigid motion is represented in the graph?

• Rotation

• Translation

• Reflection

Multiple Choice

What rigid motion is represented in the graph?

• Reflection

• Rotation

• Translation

Draw

Draw the triangle after being reflected across the Y-Axis and translated down 4 units.