Congruent Triangles

Front

What are congruent triangles?

Back

Triangles that have the same size and shape, meaning all corresponding sides and angles are equal.

Front

What is the symbol for congruence?

Back

≅

Front

If two triangles are congruent, what can be said about their corresponding angles?

Back

All corresponding angles are congruent.

Front

If ∆ABC ≅ ∆DEF, what can be concluded about angle A and angle D?

Back

∠A ≅ ∠D.

Front

What is the sum of the angles in any triangle?

Back

180°.

Front

What type of triangle has all angles less than 90°?

Back

Acute triangle.

Front

What type of triangle has one angle equal to 90°?

Back

Right triangle.

Front

What type of triangle has one angle greater than 90°?

Back

Obtuse triangle.

Front

If two sides of a triangle are equal, what can be said about the angles opposite those sides?

Back

The angles opposite the equal sides are also equal.

Front

What is the Side-Angle-Side (SAS) congruence criterion?

Back

If two sides and the included angle of one triangle are equal to two sides and the included angle of another triangle, the triangles are congruent.