Prism Extended Primitive

Create panel > Geometry button > Extended Primitives > Object Type rollout > Prism button

Create menu > Extended Primitives > Prism

Use Prism to create a three-sided prism with independently segmented sides.

Example of a prism

Procedures

To create a prism with an isosceles triangle as its base:

Choose Isosceles on the Creation Method rollout.
Drag horizontally in the viewport to define the length of Side 1 (along the X axis). Drag vertically to define the length of Sides 2 and 3 (along the Y axis).

(To constrain the base to an equilateral triangle, press Ctrl before performing this step.)
Release the mouse, and move it vertically to define the height of the prism.
Click to complete the prism.
On the Parameters rollout, alter the length of the sides as needed.

To create a prism with a scalene or obtuse triangle at its base:

Choose Base/Apex in the Creation Method rollout.
Drag horizontally in the viewport to define the length of Side 1 (along the X axis). Drag vertically to define the length of Sides 2 and 3 (along the Y axis).
Click, and then move the mouse to specify the placement of the apex of the triangle. This alters the length of sides 2 and 3, and the angles of the corners of the triangle.
Click, and then move the mouse vertically to define the height of the prism.
Click to complete the prism.

Isosceles—Draws a prism with an isosceles triangle at its base.

Base/Apex—Draws a prism with a scalene or obtuse triangle at its base.

Side (n) Length—Sets the length of triangle's corresponding side (and thus the triangle's corner angles).

Height—Sets the dimension of the prism's central axis.

Side (n) Segs—Specifies the number of segments for each side of the prism.

Height Segs—Sets the number of divisions along the prism's central axis.

Generate Mapping Coordinates—Sets up the required coordinates for applying mapped materials to the prism. Default=off.