find the length of side a

Answer:
A
Step-by-step 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 + 3² = 5²
a² + 9 = 25 ( subtract 9 from both sides )
a² = 16 ( take square root of both sides )
a = [tex]\sqrt{16}[/tex] = 4 → A
Answer:
a=4
Step-by-step explanation:
In this problem, you would use Pythagorean Theorem which is
a² + b² = c²
a and b are legs and c is the hypotenuse. In this problem, a and 3 are the legs while 5 is the hypotenuse. So...
a=a
b=3
c=5
Now substitute the values into the equation
a²+3²=5²
Exponents
a²+9=25
Subtract 9 on both sides
a²= 16
Square root on both sides
√a²=√16
Simplify
a=4
Hope this helped!