A closed shape consisting of half a circle and a diameter of that circle*. A semicircle is a half circle, formed by cutting a whole circle along a diameter line, as shown above. Any diameter of a circle cuts it into two equal semicircles. * An alternative definition is that it is an open arc.

How does a semicircle look like?

A semicircle is one half of a circle. It looks like a straight line with a circular arc connecting its ends to one another. The straight edge of the semicircle is the diameter and the arc is half the circumference of a full circle with the same diameter.

What is meant by semicircular?

1 : a half of a circle. 2 : an object or arrangement of objects in the form of a half circle.