Q:

# What is half a circle called in geometry?

A:

In geometry, the half circle is referred to as the semicircle. The semicircle is made by dividing a whole circle along its diameter. Alternatively, a semicircle could also be an open arc where a curved line represents half a circle's circumference but with no straight diameter line closing its area.

## Keep Learning

Credit: dominicotine CC-BY 2.0

A semicircle's area is always half the area of the original circle that is divided. To measure the area of a semicircle, pi needs to be multiplied to the square of the semicircle's radius before being divided into two. The perimeter of the semicircle is measured by adding the multiplication result of pi with the radius of the semicircle and twice the radius of the semicircle.

Sources:

## Related Questions

• A:

A nonagon is a nine-sided polygon in geometry. The Latin prefix "nonus" means "ninth." Like many polygons, nonagons can be regular or irregular. Regular nonagons have nine equal sides and nine interior angles equal to 140 degrees each. On the other hand, irregular nonagons have nine sides and angles that do not have to match, so they can be drawn in any way.

Filed Under:
• A:

In geometry, the term "hypotenuse" refers to the side of a right triangle that is opposite the right angle, which is also the longest side. Geometric and trigonometric problems typically use the hypotenuse in the Pythagorean Theorem.

Filed Under:
• A:

There are primarily six different types of quadrilaterals used in geometry. These are parallelogram, rectangle, square, rhombus, kite and trapezoid. Each type of quadrilateral has its own properties.