In a triangle, the sum of interior angles is 180 degrees. If two angles are 50 degrees and 60 degrees, what is the third angle?

In a triangle, the sum of interior angles is 180 degrees. If two angles are 50 degrees and 60 degrees, what is the third angle?

• A. 60 degrees
• B. 50 degrees
• C. 80 degrees
• D. 70 degrees

Answer: (D)

The sum of interior angles in any triangle is 180 degrees. Add the two given angles: 50 + 60 = 110. The third angle must make the total 180, so 180 − 110 = 70 degrees. Therefore, the third angle is 70 degrees. The other options don’t fit because adding them to 110 would not total 180 (60 gives 170, 50 gives 160, 80 gives 190).

The sum of interior angles in any triangle is 180 degrees. Add the two given angles: 50 + 60 = 110. The third angle must make the total 180, so 180 − 110 = 70 degrees. Therefore, the third angle is 70 degrees. The other options don’t fit because adding them to 110 would not total 180 (60 gives 170, 50 gives 160, 80 gives 190).