Triangle sum and Exterior Angle Theorem

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

What are the three angles in a triangle called?

Back

The three angles in a triangle are called interior angles.

Front

If one angle of a triangle is 90 degrees, what type of triangle is it?

Back

It is a right triangle.

Front

What is an exterior angle of a triangle?

Back

An exterior angle is formed by one side of the triangle and the extension of an adjacent side.

Front

What does the Exterior Angle Theorem state?

Back

The Exterior Angle Theorem states that the measure of an exterior angle is equal to the sum of the measures of the two non-adjacent interior angles.

Front

If angle A is 28 degrees and angle B is 45 degrees, what is angle C in triangle ABC?

Back

Angle C = 180 - (28 + 45) = 107 degrees.

Front

Can a triangle have angles measuring 60, 60, and 60 degrees?

Back

Yes, this is an equilateral triangle where all angles are equal.

Front

What is the measure of the third angle if two angles of a triangle are 70 degrees and 50 degrees?

Back

The third angle = 180 - (70 + 50) = 60 degrees.

Front

What is the relationship between the angles of a triangle and its exterior angles?

Back

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

Front

If angle D is 120 degrees, what are the possible measures of angles E and F in triangle DEF?

Back

Angles E and F must sum to 60 degrees (180 - 120).