Choose the required figure.
A right triangle circumscribed about a circle:

Answer with explanation:
If you want to Draw a Right Triangle Circumscribed about a circle, Draw a Right Triangle by taking Pythagorean Triplet.
Now, Draw Perpendicular Bisector of any of two sides.The Point where the two bisectors meet is center of the circle.
To find the center we have used the theorem, line from the mid point of the chord passes through the center of the circle.
From the center , that is at the point where the perpendicular bisectors meet,draw a circle Passing through three vertices of Right Triangle.