Answer:
a
Step-by-step explanation:
Using Pythagoras' identity on the right triangle
let x be the other leg to be found, then
155² = 124² + x²
24025 = 15376 + x² ( subtract 15376 from both sides )
8649 = x² ( take the square root of both sides )
= x
Hence x = 93 cm ← length of other leg → a