Answer:
a = 10
Explanation:
using Pythagoras' identity in the right triangle
the square on the hypotenuse is equal to the sum of the squares on the other 2 sides, that is
a² + 24² = 26²
a² + 576 = 676 ( subtract 576 from both sides )
a² = 100 ( take square root of both sides )
a =
= 10