## Introduction

In the world of geometry, polygons play a vital role. They are shapes with straight sides and closed figures. One interesting aspect of polygons is their angles. Understanding the angles of polygons is essential for various applications, from architecture to engineering. In this article, we will explore the 6.1 angles of polygons answer key, providing you with a comprehensive understanding of how to calculate and classify polygon angles.

## What are Polygons?

Polygons are two-dimensional shapes that consist of straight sides and closed figures. They can have any number of sides, but all sides must be straight and connected to form a closed figure. Some common examples of polygons include triangles, quadrilaterals, pentagons, hexagons, and octagons.

### Understanding Angles

Before delving into the angles of polygons, it is essential to understand the concept of angles. An angle is formed when two lines or line segments intersect. It is measured in degrees and can range from 0 degrees to 360 degrees.

## Types of Polygons Based on Angles

Polygons can be classified based on their angles. Let's explore the different types:

### 1. Acute Polygon

An acute polygon is a polygon where all interior angles are less than 90 degrees. In other words, the angles of an acute polygon are all acute angles.

### 2. Obtuse Polygon

An obtuse polygon is a polygon where at least one interior angle is greater than 90 degrees. In other words, the angles of an obtuse polygon include obtuse angles.

### 3. Right Polygon

A right polygon is a polygon where at least one interior angle measures exactly 90 degrees. In other words, the angles of a right polygon include right angles.

### 4. Equiangular Polygon

An equiangular polygon is a polygon where all interior angles are equal. In other words, the angles of an equiangular polygon are congruent.

### 5. Convex Polygon

A convex polygon is a polygon where all interior angles are less than 180 degrees. In other words, the angles of a convex polygon are all acute angles.

### 6. Concave Polygon

A concave polygon is a polygon where at least one interior angle is greater than 180 degrees. In other words, the angles of a concave polygon include obtuse and reflex angles.

## Calculating the Sum of Interior Angles

The sum of interior angles in a polygon can be calculated using the formula: (n-2) × 180 degrees, where n represents the number of sides in the polygon. Let's take a look at some examples:

### Example 1: Triangle

A triangle has three sides. Using the formula, we can calculate the sum of the interior angles:

(3-2) × 180 = 1 × 180 = 180 degrees

Therefore, the sum of the interior angles of a triangle is 180 degrees.

### Example 2: Quadrilateral

A quadrilateral has four sides. Using the formula, we can calculate the sum of the interior angles:

(4-2) × 180 = 2 × 180 = 360 degrees

Therefore, the sum of the interior angles of a quadrilateral is 360 degrees.

### Example 3: Hexagon

A hexagon has six sides. Using the formula, we can calculate the sum of the interior angles:

(6-2) × 180 = 4 × 180 = 720 degrees

Therefore, the sum of the interior angles of a hexagon is 720 degrees.

## Calculating Individual Angles

Once we know the sum of the interior angles of a polygon, we can calculate the measure of each individual angle by dividing the sum by the number of sides. Let's continue with our examples:

### Example 1: Triangle

A triangle has three sides, and we know that the sum of its interior angles is 180 degrees. To find the measure of each angle, we divide the sum by the number of sides:

180 ÷ 3 = 60 degrees

Therefore, each angle in a triangle measures 60 degrees.

### Example 2: Quadrilateral

A quadrilateral has four sides, and we know that the sum of its interior angles is 360 degrees. To find the measure of each angle, we divide the sum by the number of sides:

360 ÷ 4 = 90 degrees

Therefore, each angle in a quadrilateral measures 90 degrees.

### Example 3: Hexagon

A hexagon has six sides, and we know that the sum of its interior angles is 720 degrees. To find the measure of each angle, we divide the sum by the number of sides:

720 ÷ 6 = 120 degrees

Therefore, each angle in a hexagon measures 120 degrees.

## Applying the 6.1 Angles of Polygons Answer Key

The 6.1 angles of polygons answer key provides a comprehensive understanding of how to calculate and classify polygon angles. By utilizing the formulas and concepts discussed, you can solve various geometry problems and gain a deeper understanding of the properties of polygons.

### Example 1: Classifying a Polygon

Given a polygon with interior angles measuring 60 degrees, 90 degrees, 120 degrees, and 150 degrees, we can classify the polygon based on its angles:

Since all angles are less than 180 degrees, it is a convex polygon.

Since all angles are not equal, it is not an equiangular polygon.

Since all angles are not acute, it is not an acute polygon.

Since at least one angle is greater than 90 degrees, it is not an obtuse polygon.

Since there are no right angles, it is not a right polygon.

Therefore, the polygon can be classified as a convex polygon.

### Example 2: Finding a Missing Angle

Given a triangle with one angle measuring 40 degrees and another angle measuring 70 degrees, we can find the measure of the missing angle:

Since the sum of the interior angles of a triangle is 180 degrees, we can subtract the sum of the known angles from 180 to find the missing angle:

180 - (40 + 70) = 180 - 110 = 70 degrees

Therefore, the missing angle in the triangle measures 70 degrees.

## Conclusion

Understanding the angles of polygons is crucial for various applications in geometry. By knowing the types of polygons based on angles, calculating the sum of interior angles, and finding individual angles, you can solve geometry problems and classify polygons accurately. The 6.1 angles of polygons answer key serves as a valuable resource in the world of geometry, enabling you to navigate through the complexities of polygon angles with ease and confidence.