SOLUTION: A circle has a diameter with endpoints (-8,-1) and (-3,13). Find the center of the cicle. Find the area of the circle.

Algebra ->  Length-and-distance -> SOLUTION: A circle has a diameter with endpoints (-8,-1) and (-3,13). Find the center of the cicle. Find the area of the circle.      Log On


   



Question 157301This question is from textbook Saxon Algebra 2
: A circle has a diameter with endpoints (-8,-1) and (-3,13). Find the center of the cicle. Find the area of the circle. This question is from textbook Saxon Algebra 2

Found 2 solutions by checkley77, Fombitz:
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
(13+1)^2+(-3+8)^2=d^2
14^2+5^2=d^2
196+25=d^2
d^2=221
d=sqrt221
d=14.866 is the disstance between these 2 points.
x midpoint=(-3+8)/2=5/2=2.5
now we either add 2.5 to -8 or subtract 2.5 from -3
-8+2.5=-5.5
-3-2.5=-5.5
y midpoint=(13+3)/2=16/2=8
again add to -3 or subtract from 13.
-3+8=5
13-8=5
Thus the midpoint is (-5.5,5)
Area=2pir^2
Area=2*3.14(14.866/2)
Area=6.28*7.433
Area=46.679

Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Find the midpoint of the line connecting the two diameter endpoints.
That'll be the center of the circle.
x%5Bc%5D=%28-8%2B%28-3%29%29%2F2
x%5Bc%5D=-%2811%2F2%29
.
.
.
y%5Bc%5D=%28-1%2B13%29%2F2
y%5Bc%5D=6
.
.
.
The area of a circle is,
A%5Bc%5D=%28pi%2AD%5E2%29%2F4
The diameter of the circle is the distance between the endpoints.
D%5E2=%28x%5B1%5D-x%5B2%5D%29%5E2%2B%28y%5B1%5D-y%5B2%5D%29%5E2
D%5E2=%28-8-%28-3%29%29%5E2%2B%28-1-13%29%5E2
D%5E2=%28-5%29%5E2%2B%28-14%29%5E2
D%5E2=25%2B196
D%5E2=221
.
.
.
A%5Bc%5D=%28pi%2AD%5E2%29%2F4
A%5Bc%5D=%28pi%2A221%29%2F4
or approximately,
A%5Bc%5D=173.6
.
.
.