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Glencoe Math: Course 3, Volume 2

GM

Glencoe Math: Course 3, Volume 2 View details

4. Polygons and Angles

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Exercise 30 Page 404

The sum of the measures of the interior angles of a polygon is $(n - 2) 180,$ where $n$ represents the number of sides.

$108 0^{\circ}$

Practice makes perfect

Let's start by recalling the rule for the sum of the measures of the interior angles of a polygon.

Interior Angle Sum of a Polygon
The sum of the measures of the interior angles of a polygon is $(n - 2) 180,$ where $n$ represents the number of sides.

To find the sum of the measures of the interior angles of an octagon, we will substitute

8

for

n

in this expression.

(n - 2) 180

$n = 8$

(8 - 2) 180

▼

Evaluate

Subtract term

(6) 180

Multiply

1080

The sum of the interior angles of an octagon is

108 0^{\circ} .

Subchapter links

Guided Practice p.400

Independent Practice p.401-402

H.O.T. Problems p.402

Standardized Test Practice p.402-404

Extra Practice p.403

Common Core Review p.404