Elvin and John each had a repair made on their vacuums. The initial repair is $200. Elvin and John each have two coupons.
Each of them uses both of his coupons toward the cost of the
repair. One coupon is for $ 20 off. The other coupon is for 10%
off the repair cost. Elvin and John use their coupons in a different
order as shown below.

$5.41

step-by-step explanation:

$20 - $14.51 = $5.49.

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°.