Answer:
B
Step-by-step explanation:
a^2 + b^2 = c^2
a^2 + 2.5^2 = 3.5^2
a^2 + 6.25 = 12.25
-6.25 -6.25
a^2 = 6
√6 ≈ 2.5
2.5 + 2.5 + 3.5 = 8.5
8.5 × 3 = 25.5