Posted by **Christine** on Friday, June 24, 2005 at 4:49pm.

if A (2, -1) and B (4,7) are endpoints of a diameter of a circle, what is the area of the circle?

a)16pi

b) 17pi

c) 18pi

d)144pi

e)1156pi

Plot the two points and join 'em with a line. Now plot another point C (4, -1). And then simply run a line from B down to the new point and another one from A as well. Now u get a triangle don't u?

The height of BC will be 8cm and 2cm of that of point AC. Use pythagoras theorom to find the diameter, which is line AB. You should get 8.24

This is the length of the diameter n for finding the area u need to know the radius. So divide 8.24 by 2, which will give u 4.12

Area = r^2 times pi

Square 4.12 n u get 17

Hence the answer 17pi :)

## Answer This Question

## Related Questions

- Algebra - Points A(3,5) and B(7,10) are the endpoints of a diameter of a circle ...
- math - the number of noncollinear points needed to determine a circle Two. The ...
- Maths - 1. In the xy-coordinate plane, point A is the midpoint of the segment ...
- summer math hw - one circle has a diameter of 10 inches. a second circle has a ...
- Math - The points (4, –5) and (– 4, 1) are endpoints of a diameter of a circle. ...
- Calculus - Points (–1, 6) and (–3, 2) are endpoints of the diameter of a circle...
- 8th grade math - circle A has a raduis that is twice the length og the raduis of...
- math - A circle has an area of 25 pi cm^2.If a circle is drawn within that ...
- Math - The points (4, –5) and (– 4, 1) are endpoints of a diameter of a circle...
- Geometry - The endpoints of a diameter on a circle are a(2,1)and B(5,5). Find ...

More Related Questions