Congruent Triangles

Front

What are congruent triangles?

Back

Triangles that are identical in shape and size, meaning all corresponding sides and angles are equal.

Front

What is the symbol for congruence?

Back

The symbol for congruence is '≅'.

Front

State the criteria for triangle congruence: SSS, SAS, ASA, AAS, and HL.

Back

1. SSS (Side-Side-Side): All three sides of one triangle are equal to all three sides of another triangle. 2. SAS (Side-Angle-Side): Two sides and the included angle of one triangle are equal to two sides and the included angle of another triangle. 3. ASA (Angle-Side-Angle): Two angles and the included side of one triangle are equal to two angles and the included side of another triangle. 4. AAS (Angle-Angle-Side): Two angles and a non-included side of one triangle are equal to two angles and the corresponding non-included side of another triangle. 5. HL (Hypotenuse-Leg): In right triangles, the hypotenuse and one leg are equal.

Front

If ∠A ≅ ∠D, what can be inferred about triangles that include these angles?

Back

The triangles are congruent if the corresponding sides are also equal.

Front

What is the sum of the angles in any triangle?

Back

The sum of the angles in any triangle is always 180°.

Front

How do you find the measure of an unknown angle in a triangle?

Back

Subtract the sum of the known angles from 180°.

Front

What is an isosceles triangle?

Back

A triangle with at least two sides of equal length and the angles opposite those sides are equal.

Front

What is an equilateral triangle?

Back

A triangle where all three sides are equal in length and all three angles are equal, each measuring 60°.

Front

What is an acute triangle?

Back

A triangle where all three angles are less than 90°.

Front

What is a scalene triangle?

Back

A triangle where all three sides and all three angles are different.