What is the shape with 8 sides

A polygon with eight sides is an octagon. It also has eight vertices. A regular octagon has equal side lengths and equal interior angles, while an irregular octagon need not have either property.

Meaning and context

The interior-angle sum is (8 − 2) × 180° = 1,080°. In a regular octagon, each interior angle is 1,080° ÷ 8 = 135°. Those values follow from the number of sides and the regularity condition.

Examples and usage

An eight-sided outline can remain an octagon even when its sides differ in length. Counting the straight boundary segments is more reliable than comparing its appearance with a familiar sign or decorative pattern.

What to check

A figure with eight visible edges is not automatically a two-dimensional octagon if the drawing represents a solid. Identify whether the task concerns a flat polygon or a three-dimensional object before applying polygon formulas.

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