hi i've got the question:

find the equation of the circle which passes through the points A(2, -1) B(4, -1) and C(0, 1)

so i started by finding the mid points of two of the lines so i could use the perpendicular bisectors to find the centre. the midpoint of AB is (3, -1) and the midpoint of AC is (1, 0)

then i tried finding the gradients of AB and AC. and came up with gradient = 0 for AB. and came up with -1 for AC. how would you express this as a gradient and how would you express the perpendicular? and how would you express the equations for both

basically i'm asking, can someone show me step by step how to complete the question

thanks