A company offering short term loans agrees to lend Nick $1,200. The amount (plus interest) is repayable in one year, and the interest rate is 12% per month. What is the total amount that must be repaid? Give your answer in dollars to the nearest dollar. Do not include commas or the dollar sign in your answer. For example if your answer is $1,234.56 enter 1235.

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.

(a) the volume of the cone is 20/3 in3

hence, option a is correct.

step-by-step explanation:

let pq = qr = rs = x, and xz = y and zu = z.

if the horizontal lines are parallel, then corresponding segments are in proportion:

substitute:

therefore 3 = y = z.

xu = y + z → xu = 3 + 3 = 6