Question

help?

What is the length (in cm) of the diagonal of a rectangle that has a width of 8 cm and a diagonal of 20 cm?

Answer 1

L = Length (L-2)= Width

By Pythagoras:

L^2 + (L -2 )^2 = 10^s

L^2 + L^2 - 4L+ 4 = 100

2L^2 - 4L - 96 = 0

Divide by 2

L^2 - 2L - 48 = 0

Simplify:

(L+ 6)(L - 8) = 0

Width = 6

Length = 8

(As lengths must be positive)