Corresponding Parts of Congruent Triangles

Front

What does it mean for two triangles to be congruent?

Back

Two triangles are congruent if they have the same size and shape, meaning all corresponding sides and angles are equal.

Front

If ΔABC ≅ ΔDEF, what can we say about the corresponding sides and angles?

Back

The corresponding sides and angles of the triangles are equal: AB = DE, BC = EF, AC = DF and ∠A = ∠D, ∠B = ∠E, ∠C = ∠F.

Front

What is the Congruence Postulate?

Back

The Congruence Postulate states that if two triangles have two sides and the included angle equal, then the triangles are congruent (SAS - Side-Angle-Side).

Front

What is the Side-Side-Side (SSS) Congruence Theorem?

Back

The SSS Congruence Theorem states that if three sides of one triangle are equal to three sides of another triangle, then the triangles are congruent.

Front

How do you find the measure of a missing side in congruent triangles?

Back

Use the property that corresponding sides of congruent triangles are equal to set up an equation and solve for the missing side.

Front

If ∠A = 48° in triangle ΔABC and ΔDEF is congruent to ΔABC, what is ∠D?

Back

∠D = 48° because corresponding angles in congruent triangles are equal.

Front

What is the Angle-Angle (AA) Congruence Postulate?

Back

The AA Congruence Postulate states that if two angles of one triangle are equal to two angles of another triangle, then the triangles are similar, and if they are similar, they can be congruent.

Front

If ΔXYZ ≅ ΔRST, and XY = 5 cm, what is the length of RS?

Back

RS = 5 cm because corresponding sides of congruent triangles are equal.

Front

What is the relationship between corresponding angles in congruent triangles?

Back

Corresponding angles in congruent triangles are equal.

Front

If two triangles are congruent, how do their perimeters compare?

Back

The perimeters of congruent triangles are equal because all corresponding sides are equal.