Esther had 20 minutes to do a three-problem quiz. She spent 9 3 4 minutes on question A and 4 1 2 minutes on question B. How much time did she have left for question C?

the time left for question C is minutes

Step-by-step explanation:

The computation of the amount left for question C is shown below:

Time left for question C = Total time - time spend on question A - time spend on question B

hence, the time left for question C is minutes

1. 180°. the sum of the interior angles of a triangle is 180°, for the equilateral triangle that it has three equals side is 60°+60°+60°=180°.

2. 60°. each interior angle of a equilateral triangle is 60°

3. 120°. the measure of ∠m is 120°, the sum of the angles ∠m and ∠n is equal to 180°. so, in order to find the measure of ∠m, we have ∠m+∠n=180° > ∠m=180°-∠n > ∠m=180°-60°=120°.

4. 360°. the sum of the exterior angles of an equilateral triangle is ∠m+∠r+∠x=120°+120°+120°=360°. the exterior angles of any triangle always add 360°.