Answer:
80 ft²
Step-by-step explanation:
The carpet area will be the area of the pentagon less the 25 square feet taken up by the tree. The area of the pentagon is found by putting the given numbers into the given formula.
pentagon area = 5((7 ft)(6 ft))/2 = 105 ft²
carpet area = 105 ft² -25 ft² = 80 ft²
Peter will need 80 square feet of carpet.
