Formula for triangle perimeter is: a + b + c. In this scenario we have:
a = 3 feet 8 inches
b = 2 feet 10 inches
c = 4 feet
a + b + c =
= 3 ft + 8 in + 2 ft + 10 in + 4 ft =
= 9 ft + 18 in
We know that 1 foot is 12 inches, so we can simplify the result to this form:
10 ft + 6 in
or:
10.5 feet