Question

The equation for the circle below is x2 + y2 = 100. What is the length of the
circle's radius?

Answer 1

radius = 10

Explanation:

The equation of a circle centred at the origin is

x² + y² = r² ( where r is the radius )

x² + y² = 100 ← is in this form

with r² = 100 ( take the square root of both sides )

r =
`√(100)` = 10

Answer 2

Explanation:

x²+y² =(Radius)²

x²+y² =10². So the radius is 10