A dodecagon is a polygon v 12 sides and 12 vertices. "Do-" means "two" and "deca-" method "ten."

Dodecagon classifications

Like various other polygons, a dodecagon deserve to be divide as consistent or irregular.

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Regular dodecagonIrregular dodecagon
All sides and interior angles space congruentSides and also angles have various lengths

A dodecagon can additionally be classified as convex or concave.

A convex dodecagon is a polygon where no heat segment between any kind of two points on its border lies exterior of it. No one of the interior angles is better than 180°. Think that a convex dodecagon as bulging outwards, such as the consistent dodecagon pictured above.

Conversely, a concave dodecagon, prefer the rarely often, rarely dodecagon displayed above, has at least one line segment that have the right to be drawn in between points on its boundary however lies outside of it. Also, at least one the its interior angles is better than 180°.

A convex dodecagon go not have to be a regular dodecagon. Yet, a constant dodecagon is constantly a convex dodecagon. The dodecagon listed below is convex but plainly has sides and angles that are not congruent. This dodecagon is irregular.


Angles of a dodecagon

Dodecagons have the right to be broken into a series of triangles by diagonals attracted from that vertices. This series of triangles can be provided to find the sum of the interior angles that the dodecagon.

Diagonals are attracted from vertex A in the convex dodecagon below, creating 10 triangles. Similarly, 10 triangles can also be drawn in a concave dodecagon. Because the amount of the levels in a triangle is 180°, the amount of the inner angles of a dodecagon is 10 × 180° = 1800°.

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A constant dodecagon has actually equal internal angle measures. Due to the fact that 1800°/12 = 150°, each inner angle in a constant dodecagon has actually a measure of 150°. Also, every exterior angle has actually a measure up of 30° due to the fact that the exterior angle and also interior angle kind a directly angle.