Answer:
B
Explanation:
using the converse of Pythagoras' identity
if the longest of the 3 sides is equal to the sum of the squares on the other 2 sides then the triangle is right.
A
longest = 20 → 20² = 400
11² + 16² = 121 + 256 = 377
400 ≠ 377 , so triangle is not right
B
longest = 17 → 17² = 289
8² + 15² = 64 + 225 = 289
then this triangle is right
C
longest = 9 → 9² = 81
6² + 8² = 36 + 64 = 100
81 ≠ 100 , so this triangle is not right
D
longest = 17 → 17² = 289
6² + 15² = 36 + 225 = 261
289 ≠ 261 , so this triangle is not right