If a triangle has angles of 60 degrees and 90 degrees, what is the measure of the third angle?

If a triangle has angles of 60 degrees and 90 degrees, what is the measure of the third angle?

• A. 30 degrees
• B. 60 degrees
• C. 90 degrees
• D. 120 degrees

Answer: (A)

In a triangle, the sum of the interior angles always equals 180 degrees. To find the measure of the third angle when two angles are known, you can simply subtract the sum of the known angles from 180 degrees. In this case, the triangle has angles measuring 60 degrees and 90 degrees. Adding these two angles together: 60 degrees + 90 degrees = 150 degrees. To find the measure of the third angle, you subtract this total from 180 degrees: 180 degrees - 150 degrees = 30 degrees. Thus, the measure of the third angle in the triangle is 30 degrees, making this the correct answer.

In a triangle, the sum of the interior angles always equals 180 degrees. To find the measure of the third angle when two angles are known, you can simply subtract the sum of the known angles from 180 degrees.

In this case, the triangle has angles measuring 60 degrees and 90 degrees. Adding these two angles together:

60 degrees + 90 degrees = 150 degrees.

To find the measure of the third angle, you subtract this total from 180 degrees:

180 degrees - 150 degrees = 30 degrees.

Thus, the measure of the third angle in the triangle is 30 degrees, making this the correct answer.