Engineering Board Exam Reviewer · Polygons · medium

Find the area of a regular dodecagon inscribed in a circle of radius 10.

1. 314.16
2. 282.84
3. 150
4. 300

Answer

D. 300

Solution

The area is 12 triangles each 12r2 30°: A=12· 12(100) 30°=300.

More Polygons questions

1. A regular decagon is inscribed in a circle of radius 10. Find the length of one side.
2. Find the area of a regular octagon whose side is 4.
3. Find the apothem of a regular pentagon whose side is 10.
4. Find the area of a regular hexagon whose side is 6.
5. A polygon has 54 diagonals. How many sides does it have?
6. Each interior angle of a regular polygon measures 150°. How many sides does it have?
7. How many diagonals does a decagon have?
8. Find the measure of each exterior angle of a regular octagon.
9. Find the sum of the interior angles of a hexagon.
10. Find the sum of the interior angles of a 12-sided polygon (dodecagon).

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