Question

Mr. Franco is making a triangular cement slab and needs to set boards before he can pour the
cement. He has already set two boards that are 5 feet and 8 feet in length. What is a
reasonable range for the length of the third board that Mr. Franco could set for this triangular
cement slab?

answers-A. The third board needs to be greater than 3 feet in length.
B. The third board can be between 3 feet and 13 feet in length.
C. The third board needs to be less than 13 feet in length.
D. The third board can be 3 feet or 13 feet in length.

Answer 1

B

If two sides are a and b, the third side c must obey

a-b < c < a+b

because any side must be less than the sum of the other two.