4.1, 4.2 - Congruence, Isosceles and Equilateral triangles

Front

What is congruence in geometry?

Back

Congruence in geometry means that two figures have the same shape and size. If two triangles are congruent, all their corresponding sides and angles are equal.

Front

What are isosceles triangles?

Back

Isosceles triangles are triangles that have at least two sides of equal length. The angles opposite the equal sides are also equal.

Front

What are equilateral triangles?

Back

Equilateral triangles are triangles where all three sides are of equal length, and all three angles are equal, each measuring 60°.

Front

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

Back

The sides opposite the equal angles are also equal in length.

Front

What is the relationship between the angles in an equilateral triangle?

Back

In an equilateral triangle, all three angles are equal and each measures 60°.

Front

If triangle ABC is congruent to triangle DEF, what can be said about their corresponding angles and sides?

Back

The corresponding angles and sides of triangle ABC and triangle DEF are equal.

Front

What is the Angle-Side-Angle (ASA) congruence postulate?

Back

The ASA postulate states that if two angles and the included side of one triangle are equal to two angles and the included side of another triangle, then the two triangles are congruent.

Front

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

Back

The SAS postulate states that if two sides and the included angle of one triangle are equal to two sides and the included angle of another triangle, then the two triangles are congruent.

Front

If two triangles have two pairs of congruent sides, what can be concluded about the triangles?

Back

If two triangles have two pairs of congruent sides, they may be congruent, but additional information about the angles is needed to confirm congruence.

Front

What is the definition of a vertex in a triangle?

Back

A vertex in a triangle is a point where two sides meet. A triangle has three vertices.