Question

Btw the bit at the top thats cut off says fence is 15

Answer 1

47.4 pounds

Explanation:

First, find the height of the trapezoid. Draw the height DE. Quadrilateral ABED is a rectangle, then BE = 12 cm. Since BC = 20 cm, then EC = 20 - 12 = 8 cm.

Consider right triangle DEC. By the Pythagorean theorem,

`DE^2+EC^2=CD^2\\ \\DE^2+8^2=17^2\\ \\DE^2=289-64\\ \\DE^2=225\\ \\DE=15\ cm`

The area of the trapezoid ABCD is

`A=(AD+BC)/(2)\cdot DE=(12+20)/(2)\cdot 15=16\cdot 15=240\ cm^2`

One can cover
`100\ cm^2`, then it is needed

`(240)/(100)=2.4` cans

One can costs 19.75 pounds, then 2.4 cans cost

`19.75\cdot 2.4=47.4` pounds