Question

if two angles of a triangle sum to 100°, what is the measure of the 3rd angle?
60
80
90
100

Explanation:

Step1: Recall angle - sum property of a triangle

The sum of the interior angles of a triangle is 180°.

Step2: Calculate the third - angle

Let the sum of two angles be \(A = 100^{\circ}\), and the third angle be \(x\). Then \(x=180 - 100\).

Answer:

B. 80