Answer:
3 feet by 7 feet
Step-by-step explanation:
perimeter = 20 feet
area = 21 feet²
If the desk is a rectangle:
perimeter = 2l + 2w = 2 (l+w) = 20
2 (l+w) = 20 , divide both sides by 2
l+w = 10
area = l · w = 21
What numbers we know that have sum as 10 and their product as 21?
l + w = 10
l · w = 21
factors of 21 are 1,3,7
3+7 = 10
3 ·7 = 21
The dimensions of the desk could be 3 feet by 7 feet.
