1. Write an equation for the nth term of each arithmetic sequence.
45, 30, 15, 0, ...

Im taking that nth means 9th term so sorry if I am wrong.

1. 2. 3. 4. 5. 6. 7. 8. 9

45, 30, 15, 0, -15, - 30, - 45, - 60, - 75

So, the 9th term of the pattern is negative 75 because it decreases by 15 each time.

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°.