Triangle Sum 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

If one angle of a triangle is 90 degrees, what can you say about the other two angles?

Back

The other two angles must sum to 90 degrees, making the triangle a right triangle.

Front

What is the measure of the third angle if two angles of a triangle are 45 degrees and 55 degrees?

Back

The third angle measures 80 degrees, calculated as 180 - (45 + 55).

Front

How do you find the measure of an unknown angle in a triangle?

Back

Subtract the sum of the known angles from 180 degrees.

Front

If angle A is 30 degrees and angle B is 70 degrees, what is angle C?

Back

Angle C is 80 degrees, calculated as 180 - (30 + 70).

Front

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

Back

In an isosceles triangle, the two angles opposite the equal sides are equal.

Front

What is the measure of an angle in an equilateral triangle?

Back

Each angle in an equilateral triangle measures 60 degrees.

Front

If angle A is 40 degrees and angle B is 60 degrees, what is angle C in a triangle?

Back

Angle C is 80 degrees, calculated as 180 - (40 + 60).

Front

What is the sum of the angles in a triangle?

Back

The sum of the angles in a triangle is always 180 degrees.

Front

If one angle of a triangle is 100 degrees, what can you say about the other two angles?

Back

The other two angles must sum to 80 degrees, as 180 - 100 = 80.