find the exact length of the third side

Answer:
a = √58
Step-by-step explanation:
a² + b² = c²
Fill in the values we know:
a² + 5² = √83²
a² + 25 = 83
Subtract 25 from both sides:
a² + 25 - 25 = 83 - 25
a² = 58
Square root both sides to get 'a' by itself:
√a² = √58
a = √58