Answer:
960 cubic centimeters
Step-by-step explanation:
Base area is area of triangle: b*h*1/2
= 12*8*1/2 = 48
Base area times height is 48*20 = 960
we have

--------> equation A
----> equation B
Substitute equation A in equation B
therefore
<u>the answer is the option B</u>
From the recursive rule

it follows that


and so on. Notice how the subscript on a on the right side and the coefficient multiplied by 13 add up to n (n - 2 + 2 = n; n - 3 + 3 = n; and so on). If we continue the pattern, we'll end up with

so that the explicit rule for the n-th term in the sequence is

complementary is 90 degrees. so, you combine like terms.