Mr. Foley wants Alex to cut out a triangle to hang on the class bulletin board. He starts by cutting a line 8 inches long and two angles, 50° and 30°. What will the third angle measure? A) 80° B) 90° C) 100° D) 110°
To make a triangle, the angles must add up to 180. Add the two angles given to you: 50 + 30 = 80. Next you subtract the sum of those two angles from 180: 180 - 8 = 100. The third angle will measure C) 100°.