Ben is building a storage box for the sail of his boat. The left side of the box is 9 feet long and the right side of the box is 12 feet long. The left and right side form a right angle, as shown in the picture below.

What is the length of the base of the box?

A. 10.5 feet
B. 13.5 feet
C. 15 feet
D. 21 feet

more detail

step-by-step explanation:

option c) graph of line going through 1, 4 and 3, 10

step-by-step explanation:

let y equal to margo's coin collection

let x equal to number of years

at the begining x=0, y=1 → point=(x,y)→point=(0,1)

she adds 3 coins per year, then y=1+3x

at x=1, y=1+3(1)=1+3→y=4→point=(x,y)→point=(1,4)

at x=3, y=1+3(3)=1+9→y=10→point=(x,y)→point=(3,10)

the graph of line going through (1, 4) and (3, 10), then the option c is the correct.