O(0,0), A(0,8), T(-6,0) are the vertices of ΔOAT. Find the equation of the circle that circumscribes ΔOAT?

1 Answer
May 20, 2017

The equation is: #(x-(-3))^2+ (y - 4)^2=5^2#

Explanation:

The standard Cartesian equation for a circle is:

#(x-h)^2+ (y - k)^2=r^2" [1]"#

Please observe that the y coordinate of the center of the circle, k, is the midpoint between 0 and 8:

#k = (8+0)/2#

#k = 4#

Similarly, the x coordinate of the center of the circle, h, is the midpoint between 0 and -6:

#h = (-6+0)/2#

#h = -3#

Substitute these values into equation [1]:

#(x-(-3))^2+ (y - 4)^2=r^2" [2]"#

Use the point #(0,0)# to find the value of r:

#(0-(-3))^2+ (0 - 4)^2=r^2#

#25 = r^2#

#r = 5#

Substitute into equation [2]:

#(x-(-3))^2+ (y - 4)^2=5^2" [3]"#