Multiply the polynomials. (7x2 + 9x + 7)(9x – 4) a. 63x3 + 53x2 + 27x + 28 b. 63x3 + 53x2 + 27x – 28 c. 63x3 + 53x2 + 59x – 28 d. 63x3 + 81x2 + 27x – 28

the answer is B

Step-by-step explanation:

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°.