We know that AC is the diameter and ∠ABC=90∘.AC=2*13=26cm In right angle triangle ABC AC2=AB2+BC2 ⇒AB2+BC2=262 ⇒AB2+BC2=676 Let us check with the options. Option (A): 242+102=676 Option (B): 252+92=706≠676 Option (C):252+102=725≠676 Option (D): 242+122=720≠676.