#2**+1 **

If we extended the top base of the figure by 8m and drew a perpendicular line to the base...the additional area would create a right "Pythagorean Triple" triangle with one of the legs = 8m and a hypotenuse of 17m.....and the other leg = sqrt (17^2 - 8^2) = sqrt (225) = 15m = the length of the fence

Thus....disregarding the right triangle, we have a trapezoid with a height of 15m and two bases of 12m and 20m

So....the area of a trapezoid =

(height) / 2 * (sum of the bases ) =

15 / 2 * ( 12 + 20) =

7.5 * 32 =

240 m^2

So...we need three cans of weedkiller = 3 * 19.75 = 59.25 pounds (total cost)

CPhill
Nov 4, 2017

#2**+1 **

Best Answer

If we extended the top base of the figure by 8m and drew a perpendicular line to the base...the additional area would create a right "Pythagorean Triple" triangle with one of the legs = 8m and a hypotenuse of 17m.....and the other leg = sqrt (17^2 - 8^2) = sqrt (225) = 15m = the length of the fence

Thus....disregarding the right triangle, we have a trapezoid with a height of 15m and two bases of 12m and 20m

So....the area of a trapezoid =

(height) / 2 * (sum of the bases ) =

15 / 2 * ( 12 + 20) =

7.5 * 32 =

240 m^2

So...we need three cans of weedkiller = 3 * 19.75 = 59.25 pounds (total cost)

CPhill
Nov 4, 2017