A semi-circle is a shape with one curved side and two straight sides. The curved side is called the arc, while the two straight sides are called the radii. So, how many sides does a semi-circle have?

Technically speaking, a semi-circle has infinitely many sides. However, in practical terms, we generally consider a semi-circle to have only three sides: the arc and the two radii.

## Why a Semi Circle Has Multiple Sides

The reason why a semi-circle has infinitely many sides is because of the way that we define one side. A side of a shape is a line segment that connects two points on the shape.

So, if we consider the points on the arc of a semi-circle, there are an infinite number of points, and hence an infinite number of sides.

## How Many Corners Does a Semi Circle Have?

When we talk about the corners of a shape, we generally mean the vertices. A vertex is a point where two or more sides of a shape meet.

So, technically speaking, a semi-circle has zero vertices or corners. However, in practical terms, we often consider the two radii to be the corners of the semi-circle.

## Why a Semi Circle Has No Vertices

The reason why a semi-circle has no vertices is that the vertices are defined as points where two or more sides meet. However, as we saw above, a semi-circle only has one side: the arc.

Therefore, it doesn’t have any points where two sides meet, and hence it doesn’t have any vertices.

## Does a Semi Circle Have Two Corners?

No, a semi-circle does not have two corners. As we saw above, a semi-circle has zero vertices, which means it also has zero corners.

However, in practical terms, we often consider the two radii to be the corners of the semi-circle.

## Why Do We Consider the Radii to Be the Corners of a Semi-Circle?

The reason why we consider the radii to be the corners of a semi-circle is that they are the points where the arc meets the straight sides.

While the arc is technically the only side of a semi-circle, in practical terms, we often consider the radii to be the corners because they mark the boundary between the curved and straight sides.

## Semi Circle and a Circle

It’s worth noting that a full circle is simply a semi-circle with both ends connected. This means that a circle also has infinitely many sides and zero vertices.

The only difference between a semi-circle and a circle is that a semi-circle has two straight sides (the radii), while a circle does not.

Moreover, the term “semi-circle” is usually only used to refer to the shape formed by cutting a circle in half. So, when we talk about a semi-circle, we generally mean a shape that looks like this.

**Learn Shapes – Semicircle**

## Final Thoughts

In conclusion, a semi-circle has infinitely many sides, but in practical terms, we generally consider it to have only three sides: the arc and the two radii. Additionally, a semi-circle has no vertices or corners, but in practical terms, we often consider the two radii to be the corners of the semi-circle.