Question

The length and width of each rectangle is given. Which rectangle will not have the same perimeter as the others?
l = 12, w = 12
l = 14, w = 9
l = 8, w = 16
l = 13, w = 11

Answer 1

the perimeter is = 2*(l+w)
so just sum them and look which is different....

Answer 2

@flame619 --> Because p = 2 times the length + 2 times the width, the half perimeter is just (length + width). You could just add the two numbers (length and width) given for each rectangle above and find the sum that is different from the other three. As an example, the first option l = 12, w = 12 sums to 24. Either the other options sum to 24 or they don't. Look for the sum that differs from the other three.