Exercise 3 Page 400

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

1800^(∘)

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 a 12-gon, we will substitute 12 for n in this expression.

(n-2)180

n= 12

( 12-2)180

▼

Evaluate

Subtract term

(10)180

1800

The sum of the interior angles of a 12-gon is 1800^(∘).

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

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