Homework Help: math

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 :)

No one has answered this question yet.

Answer this Question

Related Questions

8th grade math - circle A has a raduis that is twice the length og the raduis of...
Math - Let A, C be the endpoints of the diameter of a circle and B an arbitrary ...
Calculus - Points (–1, 6) and (–3, 2) are endpoints of the diameter of...
Math - The points (4, –5) and (– 4, 1) are endpoints of a diameter of ...
math - The endpoints of the diameter of a circle are A(-1,1) and B(0.5,-3). ...
math - Line AB is the diameter of circle C. If the endpoints of the diameter ...
GEOMETRY - The diameter of a circle has endpoints P(–10, –2) and Q(4, ...
MATH HELP PLEASE - You are given two different circles. The diameter of the ...
math - A diameter of circle that has endpoints (-4,12) and (8,-2), as shown ...
Math - The points (4, –5) and (– 4, 1) are endpoints of a diameter of ...

For Further Reading

First Name:
School Subject:
Answer: