A rectangle has two pairs of sides of equal length. Explain how you can find the unknown length of two sides when the length of one side is 4 units, and the perimeter is 14 units.

Multiply 4x2 since the opposite side is the same length, and then subtract the answer (8) from the perimeter (14 units) and you’ll get 6. and then divide 6 into 2 since there is 2 more congruent sides, and you will get 3.