For the triangle below, let x be the area of the circumcircle, and let y be the area of the incircle. Compute x-y
You should have given one side of the triangle.
Side = 1
Equilateral triangle.
Sides: a = 1 b = 1 c = 1
Inradius: r = 0.289
Circumradius: R = 0.577
Area of a circle ==r^2 * Pi
x == 0.577^2 * Pi ==1.0459273 u^2 - area of the circumcircle
y == 0.289^2 * Pi ==0.26238896 u^2 - area of the incircle
x - y ==1.0459273 - 0.26238896 ==0.78353834 u^2 - difference between the area of circumcircle and the incircle.
Note: if you know the side of the equilateral triangle, then multiply everything in this answer by that side.