To get in shape for basketball tryouts, Tyrece runs sprints from his mailbox to the stop sign and back. Each unit on the graph represents 5 meters. If Tyrece ran to the stop sign and back 10 times, how many total meters did he sprint? Round to the nearest whole number. A. 806 meters
B. 312 meters
C. 403 meters
D. 650 meters

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°.