Geometry is an ancient branch of mathematics. It is all about shapes and sizes. Geometry helps us understand how objects are related to each other. Practical geometry helps us in many ways, such as measuring distances, calculating areas, drawing shapes, etc.

You come across a lot of different terms while dealing with practical geometry and trigonometry.

Opposite, adjacent, and hypotenuse are three terms used to describe the sides of a right triangle. They’re used most often in math and geometry, but they can be helpful to know if you’re studying trigonometry or trigonometric functions.

The main difference between these three terms is that the opposite is the side that’s opposite from the angle described. Adjacent is the side that lies next to the angle described. Finally, the hypotenuse of a triangle is its longest side, and it always runs perpendicular to the other two sides.

*Let’s discuss these three terms in detail.*

## What Is Meant By Opposite In Right Triangle?

**In a right triangle, it is the side that is opposite the 90-degree angle.**

The opposite side can be determined by using a trigonometric function called sine. You can do this by drawing a line from the angle’s vertex to its hypotenuse and then measuring how far that line is from each leg of the triangle. The length of this line will determine which side is opposite or opposite to the given angle.

## What Is Meant By Adjacent In Right Triangle?

**Adjacent means two things. It can mean “next to” or “on the same side as.”**

Adjacent is a term used to describe the relationship between two sides of a right triangle when one of those sides is adjacent to the hypotenuse.

The hypotenuse is the side opposite the right angle, and the other two sides are called legs. These are the sides that are adjacent to each other.

## What Is Meant By Hypotenuse In Right Triangle?

Usually, the hypotenuse of a right triangle sits opposite the right angle.

The hypotenuse works as a measurement unit and is also known as the longest side of a right triangle. The hypotenuse is always longer than both other sides of a right triangle.

The word “hypotenuse” comes from Greek and means “length,” which accurately describes this particular side’s role in a right triangle.

The hypotenuse is also known as the “leg opposite the right angle,” as it shares this quality with its counterpart, the opposite leg (the one that does not contain the 90-degree angle).

## Difference Between Opposite, Adjacent, And Hypotenuse

The differences between the three sides of a triangle are as follows:

### Opposite

**The side opposite another side is the one that makes an angle with it, and it’s also the longest side of the triangle. For example, if you have a triangle with a 90-degree angle, its opposite side will be twice as long as its adjacent side.**

### Adjacent

**The adjacent side is the one that shares a vertex (the corner) with another side. For example, when there are two right triangles, where one has a 90-degree angle, their adjacent sides will be equal in length.**

### Hypotenuse

**Every triangle has its longest side as its hypotenuse. It represents the distance from one vertex to the other on an imaginary line through both vertices (perpendicular to all sides).**

Here is the table summarizing these differences.

Opposite | The two sides are not adjacent to each other. |

Adjacent | The two sides are next to each other. |

Hypotenuse | The longest side of a right triangle. |

*Opposite vs. Adjacent vs. Hypotenuse*

## How Do You Label Opposite, Hypotenuse, And Adjacent?

To label the opposite, hypotenuse, and adjacent sides of a right triangle, you must know what kind of right triangle you’re dealing with.

- If you have an isosceles right triangle—one with two sides of equal length—you can label the opposite side (which is also the hypotenuse) “a” and then label the adjacent side “b.”
- If you have an equilateral right triangle—one with three equal sides—you can label the hypotenuse “c” and then label one of the adjacent sides “a” and the other adjacent side “b.”
- If you have an obtuse-angled triangle (the angle between two sides is greater than 90 degrees), then you can say that one side is opposite to another side.

Here is a video identifying all these sides in a triangle.

## What’s The Opposite Of Hypotenuse?

The hypotenuse is the longest side of a right triangle. The opposite of the hypotenuse is the shortest side of a right triangle.

## Is The Adjacent Side Always The Shortest Side?

The adjacent side is not always the shortest, but it is in many cases. Triangles have an adjacent side that shares a vertex with the given angle. In other words, the side forms a right angle with the given angle.

The adjacent side is always shorter than the opposite side, and another side of the triangle forms an angle equal to 90 degrees at the given angle. The opposite side is shorter than the hypotenuse, the longest side of any right triangle.

## Bottom Line

- Opposite, adjacent, and hypotenuse are the terms associated with the right-angle triangle and are used in the geometric explanations of mathematical problems.
- Opposite sides are a pair of parallel lines with endpoints on the same line and a common endpoint.
- Adjacent sides are a pair of parallel lines with endpoints on the same line but do not have a common endpoint.
- The hypotenuse is the longest side in a right triangle.