Question

4. A rectangle with area 1,600 m2 is 4 times as long as it is wide. What is the sum of the diagonals?

Answer 1

We need to write out algebraic equations to describe the information we have, then solve them using substitution.

We will define length as a and width as b.

we know that a x b = 1600 cm3 (area = length x width)

and a=4b

So, we can substitute the vaule 4b for a in the first equation:

4b x b = 1600

we can simplify to 4b2 = 1600

divide both sides by 4:

b2 = 400

take the square root of each side:

b = √400

b=20

So we know the width = 20

length = 4 x width = 80