Answer
Equilateral triangle.
Work Step by Step
Using the compass to draw a semicircle means that the distance between the compass tip and the pencil is the radius of the circle. The distance from the point marked before to the edge of the circle is the radius. The second length can be used to construct second side. And finally, you can add third side (which is the radius of the circle so congruent). At the end we get triangle with equal sides, therefore, it is equilateral triangle.