One side of the rectangle is 12cm. Find: a) the perimeter of the rectangle if its area is 84cm²;

One side of the rectangle is 12cm. Find: a) the perimeter of the rectangle if its area is 84cm²; b) the area of the rectangle if its perimeter is 40 cm.

Problem a)
1. find what is the other side of the rectangle.
84/12 = 7 centimeters.
2. Find what the perimeter of the rectangle is.
12 + 12 + 7 + 7 = 38 centimeters.
Answer: The perimeter of the rectangle is 38 centimeters.
Problem b)
2. Find what is the sum of the two sides of the rectangle.
12 + 12 = 24 centimeters.
3. Find what is the sum of the other two sides of the rectangle.
40-24 = 16 centimeters.
4. Find what is the other side of the rectangle.
16/2 = 8 centimeters.
5. Find the area of the rectangle.
12 * 8 = 96 sq. Cm.
Answer: The area of the rectangle is 96 sq. Cm.