The length of a rectangle is 1 cm less than 3 times the width. The rectangle has an area of 10 square cm.

Question

Find the exact length of a diagonal of this rectangle.

Answer 1

10 = w(3w - 1)

10 = 3w² - w

0 = 3w² - w - 10

0 = (3w +1)(w - 2)

The width is 2 and the length is 5

d² = 2² + 5²