Triangle Sum Theorem 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.

Tags

CCSS.8.G.A.5

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.

Tags

CCSS.8.G.A.5

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

State the Exterior Angle Theorem.

Back

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

Tags

CCSS.8.G.A.5

Front

If the exterior angle of a triangle is 146 degrees, what is the sum of the two remote interior angles?

Back

The sum of the two remote interior angles is 146 degrees.

Tags

CCSS.8.G.A.5

Front

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

Back

To find a missing angle, subtract the sum of the known angles from 180 degrees.

Tags

CCSS.8.G.A.5

Front

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

Back

Each angle in an equilateral triangle measures 60 degrees.

Tags

CCSS.8.G.A.5

Front

If two angles of a triangle are 50 degrees and 85 degrees, what is the measure of the third angle?

Back

The third angle measures 45 degrees (180 - 50 - 85 = 45).

Tags

CCSS.8.G.A.5

Front

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

Back

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

Tags

CCSS.8.G.A.5

Front

If the remote interior angles of a triangle are represented as 5y + 3 and 4y + 8, how do you find y if the exterior angle is 146 degrees?

Back

Set up the equation: 5y + 3 + 4y + 8 = 146 and solve for y.

Tags

CCSS.8.G.A.5