Respuesta :

Answer:

C

Step-by-step explanation:

Follow Pythagorean Theorem. a^2 + b^2 = c^2

We know b and c:

a^2 + 12^2 = 13^2

a^2 + 144 = 169

a^2 = 25

a = √25

a = 5

The answer is C because we know side a = 5

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