Question

The center of circle `Q` has coordinates `(3, -2)`. If circle `Q` passes through `R(7, 1),` what is the length of its diameter?

Answer 1

Length of diameter is `10`.

Explanation:

As circle, whose centre is `Q(3,-2)`, passes through `R(7,1)`, `R` is on circumference

and as distance between centre and any point on circumference is radius

the radius is `sqrt((7-3)^2+(1-(-2))^2)`

= `sqrt(4^2+3^2)=sqrt(16+9)=sqrt25=5`

And as radius is `5`, length of diameter is `10`.