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# The Exterior Angle of a Triangle in Geometry

Blog Introduction: The exterior angle of a triangle is the angle between any side of the triangle and the extension of the adjacent side. In other words, it is the angle that is formed outside of the triangle.

To better understand this concept, let’s look at an example. Say we have a triangle with sides that measure 3, 4, and 5. If we extend the side that measures 3, we create an exterior angle. This angle can be measured and is equal to ____ degrees.

## How to Measure the Exterior Angle of a Triangle

There are a few different ways that you can measure the exterior angle of a triangle. The first way is to use a protractor. If you don’t have a protractor, you can also use a ruler or tape measure.

First, you need to find the midpoint of the side of the triangle that you want to extend. To do this, you will need to divide the length of that side by 2. Once you have found the midpoint, you can then draw a line from the midpoint to the vertex (the point where two sides of a triangle meet) that is opposite of the side you are extending.

Once you have drawn this line, you can then use your protractor to measure the angle created. This angle is your exterior angle!

Another way to measure the exterior angle of a triangle is by using geometry formulas. The formula for finding the exterior angle of a triangle when given the other two angles is: exterior angle = sum of interior angles - 180° . So, if we know that our interior angles are 60° and 80° , our exterior angle would be calculated as follows: exterior angle = 60° + 80° - 180° . This gives us an answer of 20° .

## Conclusion:

The exterior angle of a triangle is an important concept in geometry. It is defined as the angle between any side of the triangle and its extended adjacent side. There are several different ways that you can measure the exterior angle of a triangle; one way is by using a protractor, and another way is by using geometry formulas. Understanding and being able to calculate the exterior angle of a triangle will help you in your future mathematical pursuits!

## FAQ

### What is an exterior angle in a triangle?

An exterior angle of a triangle is the angle between any side of the triangle and its extended adjacent side.

### What is an exterior angle in geometry?

An exterior angle in geometry is defined as the angle between any side of a geometric shape and its extended adjacent side.

### What is exterior angle short answer?

An exterior angle is an angle that is outside of a given geometric shape. It can be measured by using a protractor or by using geometry formulas.

### What is the exterior of a triangle called?

The exterior of a triangle is the side that is opposite of the interior angles. It is also the side that is not connected to any other sides of the triangle.