Question

If a point B(2,5) lies on a circle with center at origin,then what will be the length of the

radius?

Answer 1

r =
`√(29)`

Explanation:

The distance from the centre to a point on the circle is the radius r

Calculate r using the distance formula

r =
`\sqrt{(x_(2)-x_(1))^2+(y_(2)-y_(1))^2 }`

with (x₁, y₁ ) = (0, 0 ) and (x₂, y₂ ) = (2, 5 )

r =
`√((2-0)^2+(5-0)^2)`

=
`√(2^2+5^2)`

=
`√(4+25)`

=
`√(29)`