Angle Sum Theorem, Exterior Angle Theorem, Classifying Triangles

Front

What is the Angle Sum Theorem?

Back

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

Front

What is the measure of angle b if angle a is 90° and angle c is 54°?

Back

36°

Front

Define an isosceles triangle.

Back

An isosceles triangle is a triangle that has at least two sides of equal length.

Front

What is the Exterior Angle Theorem?

Back

The Exterior Angle Theorem states that the measure of an exterior angle of a triangle is equal to the sum of the measures of the two opposite interior angles.

Front

Classify a triangle with angles measuring 90°, 45°, and 45°.

Back

Right isosceles triangle.

Front

What is the measure of the third angle in a triangle if the other two angles are 70° and 40°?

Back

70° (because 70° + 40° + 70° = 180°).

Front

What is a scalene triangle?

Back

A scalene triangle is a triangle in which all three sides are of different lengths.

Front

If one angle of a triangle is 120°, what can you say about the other two angles?

Back

The other two angles must be acute (less than 90°) because the sum of all angles must equal 180°.

Front

What is the classification of a triangle with one angle greater than 90°?

Back

Obtuse triangle.

Front

If angle A is 30° and angle B is 60°, what is angle C?

Back

Angle C is 90° (30° + 60° + 90° = 180°).