# How do you write an equation for a circle with center (2,4) and passes through point (5, 9)?

##### 1 Answer

Apr 16, 2016

#### Explanation:

The radius can be found using Pythagoras Theorem

#r = sqrt{(5-2)^2 + (9-4)^2} = sqrt34#

For a circle with radius

#(x-a)^2 + (y-b)^2 = r^2#

Therefore. for a circle with radius

#(x-2)^2 + (y-4)^2 = 34#