Question

a point (-1,-2)is on a circle with centre (1,2）what is the circumference of the circle?

Answer 1

r= square root ((-1-1)^2+(-2-2)^2)
= square root (4+16)
=4 root 5 units
Circumference= 2× pie×r
= 2× 22/ 7×4root5
=(44×4 root 5)/7