Answer:
A
Explanation:
Using Pythagoras' identity on the right triangle.
The square on the hypotenuse is equal to the sum of the squares on the other 2 sides, that is
t² + 12² = 13²
t² + 144 = 169 ( subtract 144 from both sides )
t² = 25 ( take the square root of both sides )
t =
= 5 → A