🧱 See It
Recall the pattern: find the base's area, then multiply by height. A rectangular-prism box uses a rectangle base. A cylinder uses a circle base. A triangular prism uses a triangle base. Same pattern every time — only the base shape changes.
✏️ Draw It
A real triangular prism — the front triangular face is solid; the hidden edges behind it are dashed:
The front triangle is the prism's base shape — base and height marked with a right-angle corner. The prism's length runs straight back into the page.
🔢 Write It
Volume = (triangle base area) × prism length
where triangle base area = (base × height) ÷ 2
Two separate steps, in order. Step 1: find the triangular base's area. Step 2: multiply by the prism's length. Never all in one pass.
💡 Worked Examples
Example — triangular base: base = 6 cm, height = 4 cm; prism length = 10 cm
- Step 1, triangle area:
(6 × 4) ÷ 2 = 12 cm² - Step 2, multiply by length:
12 × 10 = 120 - Answer:
Volume = 120 cm³
🧠 Quick Reference
Volume of a triangular prism = (triangle base area) × length. Find the triangle's area as its own separate labeled step first — using (base × height) ÷ 2 — then multiply by the prism's length second. Never combine into one calculation.