Help please I tried to solve cant come up with an answer on here

Answer:
B. 41 cm
Step-by-step explanation:
First, find the missing side of the triangle's length.
a^2 + b^2 = c^2
11^2 + 13^2 = c^2
c = 17
Then add all the side up
11 + 13 + 17 = 41