Answer:
D
Step-by-step explanation:
Consider the right triangle on the right with base = [tex]\frac{1}{2}[/tex] x
Using Pythagoras' identity
The square on the hypotenuse is equal to the sun of the squares on the other 2 sides, that is
([tex]\frac{1}{2}[/tex] x )² + 12² = 13², that is
[tex]\frac{1}{4}[/tex] x² + 144 = 169 ( subtract 144 from both sides )
[tex]\frac{1}{4}[/tex] x² = 25
Multiply both sides by 4
x² = 100 ( take the square root of both sides )
x = [tex]\sqrt{100}[/tex] = 10 → D
