Question

A rectangular field has an area 28800 sq meter. Its length is twice as long as its width. What is the length of its sides?

Answer 1

W= width L= length = 2W

Area of Rectangle= Length * Widthsubstitute the area and the value of L in the formula
28,800 m^2= 2W * W
28,800= 2W^2divide both sides by 2 in an effort to isolate the variable w
14,400= W^2take the square root of both sides
√14,400= W^2
we want the negative and positive root of the radicand (the number under the radical symbol - 14,400 in this case)
120= w OR -120= w


LENGTHL= 2W= 2(120)= 240 meters

ANSWER: The side lengths are W= 120 m; L= 240 m.  Even though W= -120 too, it is not a valid solution in this case since a field cannot have a negative value.

Hope this helps!  :)