SOLUTION: The area of a rectangle is 168 square ft. Determine the length, width, and diagonal of a rectangle if the length is 3 feet greater than 3 times the width.

Algebra ->  Rectangles -> SOLUTION: The area of a rectangle is 168 square ft. Determine the length, width, and diagonal of a rectangle if the length is 3 feet greater than 3 times the width.      Log On


   

Question 362089: The area of a rectangle is 168 square ft. Determine the length, width, and diagonal of a rectangle if the length is 3 feet greater than 3 times the width.
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi, 

Let x represent the width.  then the length is (3x+3)

Area is l*w

(3x+3)*x == 168ft^2

3x^2 + 3x = 168ft2

3x^ + 3x - 168 = 0

x^ + x - 56 =0

factoring

(x - 8)(x+7)= 0

x = 8  the width is 8ft

x = -7 cannot use

width is 8 and the length is 27 (3*8 + 3)

finding d the diagonal implementing the Pythagorean Therem

8^2+ 27^2 = d^2

d = 28.160 ft