Hi,
For any type of triangle, follow these steps:
1). Chose the middle of any side of triangle, and draw a perpendicular on that side, perpendicular has to be on that middle point. Let us say perpendicular is line 1;
2). Chose the middle of any other side of triangle, and draw a perpendicular on that side, perpendicular has to be on that middle point. Let us say perpendicular is line 2.
The intersection of line 1 and line 2 is the center of the circle you are looking for, just pick one of the triangle vertices, the radius of that circle is line between circle center, and that vertex.
When you will draw the circle with a pair of compasses, you will see that circle will "miraculously" go over each vertex of the triangle.
Have you understood ?
Cheers,
Green eyes.
