Question

PLEASE HELP
I've tried putting all my working out into the box but it said wrong to..​

Answer 1

£59.25

Explanation:

It appears you can measure the height of the trapezoid [trapezium :-) ??]. If you can't, you can use the Pythagorean Theorem (image attached). Draw a line from the upper right-hand corner down to the baseline--the 20m side. You'll form a right triangle with one leg h , hypotenuse 17m and the other leg 8m (the difference between 20m and 12m).

(leg)^2 + (leg)^2 = (hypotenuse)^2

h^2 + 8^2 = 17^2

h^2 + 64 = 289

h^2 = 225

h = 15m

The area of the trapezium is
`A=(1)/(2)h\left(b_1+b_2\right)` where the b's are the lengths of the two bases (upper and lower sides).

`A=(1)/(2)(15)(12+20)=(1)/(2)(480) = 240` m^2

One can of weedkiller covers 100 m^2 of area. You'll need 3 cans (2 cans isn't enough, and you can't buy a fraction of a can). Tricky question!

Three cans will cost 3 x 19.75 pounds = £59.25