5.1-5.4 Triangle Relationships

Front

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

Back

Obtuse triangle.

Front

What is the classification of a triangle with all sides of different lengths?

Back

Scalene triangle.

Front

What is the Triangle Sum Theorem?

Back

The sum of the angles in a triangle is always 180°: m∠A + m∠B + m∠C = 180°.

Front

What is the measure of each angle in an equiangular triangle?

Back

60°.

Front

What is an isosceles triangle?

Back

A triangle with at least two sides of equal length.

Front

What is a right triangle?

Back

A triangle that has one angle measuring 90°.

Front

What is the Exterior Angle Theorem?

Back

The measure of an exterior angle is equal to the sum of the measures of the two opposite interior angles.

Front

What is the Third Angle Theorem?

Back

If two angles of a triangle are known, the third angle can be found by subtracting the sum of the known angles from 180°.

Front

What is the base of a triangle?

Back

Any one of the sides of a triangle can be considered the base, often the one on which the triangle is thought to 'stand'.

Front

What is the definition of complementary angles?

Back

Two angles that add up to 90°.