Finding Unknown Angle Measures Parallel Lines and Triangles

The Triangle Sum Theorem states that the sum of all angles in a triangle is ______. 

• 45°
• 90°
• 180°
• 360°

What is the measure of the missing angle?

• 82
• 43
• 55
• 180

Solve for x.

• -11
• 9
• -9
• 10

Solve for x.

• 8
• -10
• -7
• 6

Solve for x.

• 5
• 12
• -7
• -6

Solve for x.

• 4
• 6
• 7
• -10

Solve for x.

• 7
• 9
• -11
• -6

Find the measure of angle A.

• 20 degrees
• 22 degrees
• 21 degrees
• 100 degrees

Find the measure of angle A.

• 21 degrees
• 31 degrees
• 128 degrees
• 24 degrees

Find the measure of angle A.

• 30 degrees
• 160 degrees
• 140 degrees
• 32 degrees