Triangle Sum, Classifying Triangles, & Congruent Triangles

Front

What is the Triangle Sum Theorem?

Back

The Triangle Sum Theorem states that the sum of the interior angles of a triangle is always 180 degrees.

Front

How do you classify triangles based on their angles?

Back

Triangles can be classified as acute (all angles < 90°), right (one angle = 90°), or obtuse (one angle > 90°).

Front

How do you classify triangles based on their sides?

Back

Triangles can be classified as equilateral (all sides equal), isosceles (two sides equal), or scalene (no sides equal).

Front

What is a congruent triangle?

Back

Congruent triangles are triangles that are identical in shape and size, meaning their corresponding sides and angles are equal.

Front

What is the symbol for congruence?

Back

The symbol for congruence is '≅'.

Front

If m∠A = 45° and m∠B = 55°, what is m∠C in triangle ABC?

Back

m∠C = 180° - (m∠A + m∠B) = 180° - (45° + 55°) = 80°.

Front

What is the relationship between the angles in a right triangle?

Back

In a right triangle, one angle is 90°, and the sum of the other two angles is 90°.

Front

What does it mean for triangles to be similar?

Back

Similar triangles have the same shape but may differ in size; their corresponding angles are equal, and their sides are in proportion.

Front

What is the Angle-Angle (AA) criterion for triangle similarity?

Back

If two angles of one triangle are equal to two angles of another triangle, the triangles are similar.

Front

How can you determine if two triangles are congruent using SSS?

Back

Two triangles are congruent by the Side-Side-Side (SSS) criterion if all three sides of one triangle are equal to the three sides of another triangle.