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A regular nonagon has an area of 102.4 and one side length measures 7 units long. Find the apothem. Round to the nearest tenth, if necessary.

User Roarster
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1 Answer

23 votes
23 votes

Answer:

Apothem = 3.3 units

Explanation:

A regular nonagon has an area of 102.4 and one side length measures 7 units long. Find the apothem. Round to the nearest tenth, if necessary.

The formula to find the area of a polygon when given Apothem and Side length =

A = 1/2 × a × p

Where p = no of sides of polygon × side length

In the above question,

We are given a polygon = nonagon = 9 sides

Side length = 7 units

p = 9 × 7 = 63 units

Area = 102.4 square units

Apothem = a = ?

We substitute into the formula

102.4 = 1/2 × a × 63

102.4 = 63a/2

Cross Multiply

102.4 × 2 = 63a

Divide both sides by 63

a = 102.4 × 2/63

a = 3.2507936508 units

Approximately to the nearest tenth = 3.3 units

User Mark Hatton
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