# Complete Angle in Geometry

## What Is a Complete Angle?

A complete angle is a geometric figure that is made up of two rays or line segments with a common endpoint. It is measured in degrees, with a full circle being 360 degrees. The angle can also be described by its vertex, which is the endpoint of both rays. A complete angle is one of the fundamental concepts of geometry.

## Types of Angles

There are three main types of angles: right, acute, and obtuse. A right angle measures exactly 90 degrees and is often represented by a square. An acute angle measures less than 90 degrees, while an obtuse angle measures more than 90 degrees. The acute and obtuse angles are often described as narrow and wide angles, respectively.

## Angles in Trigonometry

In trigonometry, angles are used to measure the relationship between sides of a triangle. The angles are used to calculate the triangle’s area and its other properties. Trigonometry is used in many fields, such as engineering, astronomy, and navigation.

## How to Calculate an Angle

Calculating an angle is fairly straightforward. To begin, measure the length of each side of the triangle and then use the Pythagorean theorem to calculate the hypotenuse. Next, use the law of cosines to calculate the angle in the triangle. Finally, use the law of sines to calculate the remaining angles in the triangle.

## Practice Problems

Let's practice calculating angles with these geometry problems:

- Find the angles of a triangle where the sides measure 4, 6, and 8.
- What is the angle between two lines that intersect at a right angle?
- What is the measure of an obtuse angle?
- What is the measure of an acute angle?
- Calculate the angles of a quadrilateral.
- What is the measure of a reflex angle?

### Answers

- The angles of the triangle are 25.3°, 53.1°, and 101.6°.
- 90°
- An obtuse angle measures more than 90°.
- An acute angle measures less than 90°.
- The angles of the quadrilateral depend on the shape of the quadrilateral.
- A reflex angle measures more than 180°.

## Summary

A complete angle is a geometric figure that is made up of two rays or line segments with a common endpoint. It is measured in degrees, with a full circle being 360 degrees. There are three main types of angles: right, acute, and obtuse. In trigonometry, angles are used to measure the relationship between sides of a triangle. To calculate an angle, measure the length of each side of the triangle and then use the Pythagorean theorem, the law of cosines, and the law of sines.

## FAQ

### What is the measure of a complete angle?

A complete angle has an angle measure of 360°.

### What shape has four complete angles?

A shape that has four complete angles is a square.