To find the volume, first find the area of the triangle on top, which has a base of 10 and a height of 16. The area is 160 square units.
Mult. this area by the height of the solid, which is 4.
Then the volume of the solid is 640 cubic units.
Answer and step-by-step explanation:
cos = adj/hyp (in a right triangle)
cos0 = 3/5
adj = 3
hyp = 5
opp = sqrt( 5^2 - 3^2) = sqrt( 25-9) = sqrt(16) = 4 (Pythogorean theorem)
tan0 = opp/adj = 4/3
In order to determine the money you have to invest now to obtain $100,000 after 18 years, use the following formula:

where,
P: principal = ?
A: amount after t years = 100,000
r: APR in decimal form = 0.11 (11%)
n: times of the compounded interest at year = 4 (quarterly)
t: time = 18 (years)
Solve the equation above for P, replace the values of the other parameters and simplify:

Hence, you need to invest approimately $14,181.04 to obtain $100,000 after 18 years.
D:24 square units because u add all the units