Answer: The width is 9 units and the length is 20 units
Explanation:
Perimeter is length + length + width + width, (P = 2l + 2w)
76 = 2(w+20) + 2w
76 = 2w + 40 + 2w
76 = 4w + 40
Subtract 40 on both sides
36 = 4w
Divide both sides by 4
9 = w
That means the length is 29 and the width is 9. To check out work, add 29+29+9+9 to get 76. Our answer is correct.