# Antiprism Definition

In geometry, **antiprism shapes** like a **prism **but **having two end nodes**, also known as **identical polygons**, twisted and connected with a chain of triangles.

Or in simple words, **antiprism **is determined as the **classes or subgroups of prismatoids**.

For instance, an octagonal antiprism is shown in the below diagram:

**Note:**

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You can observe that this octagonal antiprism is combined with two identical parallel octagons. One is twisted, triangles join them.

To calculate the twist in antiprism, you have to divide 180° with the number of sides observed in shape.

Below is a square antiprism diagram, having a twist at 45° (180°/4 = 45°).