Answer:
A semicircle can be drawn by first drawing a diameter of a circle, which is a line segment connecting two points on the circumference that passes through the center of the circle. Then, the semicircle can be constructed by drawing an arc that is half of the circumference of the circle and connecting the ends of the arc to the endpoints of the diameter.
A quarter circle can be drawn in a similar way, but instead of drawing an arc that is half of the circumference, you would draw an arc that is a quarter of the circumference. To do this, you would need to find the central angle that subtends the arc and divide it by 4. The quarter circle can then be constructed by drawing an arc with this central angle and connecting the ends of the arc to the endpoints of a radius of the circle, rather than the diameter.
In both cases, you can use a compass or a protractor to accurately draw the arcs.