Question

Circle R has diameter ST with endpoints S(4, 5) and T(-2, 3). What are the circumference and area of the circle?

Answer 1

Circumference is `19.87` and area is `31.416`

Explanation:

The distance between endpoints `(4,5)` and `(-2,3)` of the diameter `ST` of circle `R` is

`sqrt(-2-4)^2+(3-5)^2=sqrt(36+4)=sqrt40=sqrt(2xx2xx10=2sqrt10)`

Hence, radius of the circle `R` is `(2sqrt10)/2=sqrt10`

and Circumference of circle is given by `2pir` i.e.

`2pixxsqrt10=2xx3.1416xx3.1623=19.87`

and Area of circle is given by `pir^2` i.e. `3.1416xx(sqrt10)^2=3.1416xx10=31.416`