If △ABC and △XYZ are right-angled triangles, right angled at B and Y respectively, then for what value of x will △ABC be congruent to △XYZ ?
AB = XY (given)
∠ABC = ∠XYZ = 90∘ (given)
If BC = YZ = 8 cm, then the two triangles are congruent by SAS congruency rule.
Hence, x = 8 cm.