Question

The width rectangle is three less than twice its length. If the area of the rectangle is 193 cm² what is the length of the diagonal?

Answer 1

Explanation:

Givens

Let the Length = L

Let the width = w

w = 2*L - 3

Area = L * w

Area = 193

Solution

Area = 193

193 = L*(2L - 3)

193 = 2L^2 - 3L Subtract 193 from both sides.

2L^2 - 3L - 193 = 0

You have to use the quadratic formula get the answer. Without going through all all that, I will tell you that the only value you can use for L is 10.6

L = 10.6

w = 2* 10.6 - 3 = 18.4

But you want the diagonal. Use the Pythagorean Theorem to get it.

Diagonal^2 = L^2 + w^2

Diangonal^2 = 10.6^2 + 18.4^2

Diagonal^2 = 450.92 Take the square root of both sides

√diagonal^2 = √450.92

Answer

The diagonal is 21,23