8th Grade Math Worksheets - Free Printable

I'll solve the problem by finding the measure of the indicated angle in each triangle. I need to use the fact that the sum of the interior angles in any triangle is always 180°.

Let me go through each triangle one by one:

Triangle 1: Angles are 50° and 70°, find ∠A.
∠A = 180° - 50° - 70° = 60°

Triangle 2: Angles are 90° and 30°, find ∠B.
∠B = 180° - 90° - 30° = 60°

Triangle 3: Angles are 45° and 65°, find ∠C.
∠C = 180° - 45° - 65° = 70°

Triangle 4: Angles are 55° and 75°, find ∠F.
∠F = 180° - 55° - 75° = 50°

Triangle 5: Angles are 30° and 40°, find ∠H.
∠H = 180° - 30° - 40° = 110°

Triangle 6: Angles are 50° and 50°, find ∠Y.
∠Y = 180° - 50° - 50° = 80°

Triangle 7: Angles are 60° and 60°, find ∠K.
∠K = 180° - 60° - 60° = 60°

Triangle 8: Angles are 80° and 50°, find ∠L.
∠L = 180° - 80° - 50° = 50°

Triangle 9: Angles are 70° and 70°, find ∠C.
∠C = 180° - 70° - 70° = 40°

The solution for each triangle is based on the fundamental property that the sum of all interior angles in a triangle equals 180 degrees. For each triangle, I subtracted the two given angles from 180° to find the missing angle.