Triangle Perimeter Table: Perimeter by Side a
Reference table of perimeter for Triangle Perimeter across a range of side a values — exact, engine-computed figures you can read off at a glance.
Triangle Perimeter Calculator
Verified formula Updated Jun 2026 Private — runs on your device
Verified formula
Private
Perimeter
12.0000
For general information only — not financial, tax, legal or medical advice. Verify before you rely on it.
How to use the Triangle Perimeter Calculator
The Triangle Perimeter Calculator works out your perimeter in an instant. Enter side a, side b and side c and the result updates as you type — it is free, needs no sign-up, and runs entirely in your browser so your figures stay private.
- Enter the side a.
- Enter the side b.
- Enter the side c.
- Read off your perimeter — the calculator updates automatically, with no button to press.
Formula
The Triangle Perimeter Calculator uses the formula:
Perimeter = Side a + Side b + Side c
Worked example
For example, with side a of 3, side b of 4 and side c of 5, the perimeter is 12.0000.
| Side a | 3 |
|---|---|
| Side b | 4 |
| Side c | 5 |
| Perimeter | 12.0000 |
|---|
Results are estimates for educational use, not professional advice.
Key terms explained
- Perimeter
- The total distance around the outside of a two-dimensional shape.
Frequently asked questions
Add the lengths of all three sides. A 3-4-5 triangle has a perimeter of 12.
No. The perimeter is the sum of the sides for any triangle, whether scalene, isosceles or equilateral.
You need all three sides for the perimeter, unless extra information lets you find the third.
Perimeter is the distance around the triangle; area is the space it encloses.
The Triangle Perimeter Calculator uses the formula: Perimeter = Side a + Side b + Side c. For example, with side a of 3, side b of 4 and side c of 5, the perimeter is 12.0000.
Enter the side a. Enter the side b. Enter the side c. Read off your perimeter — the calculator updates automatically, with no button to press.
Related guides
How to Calculate Triangle Perimeter: Formula, Steps & Examples
Learn how to calculate Triangle Perimeter — the formula explained step by step, with worked examples and a free calculator to check your answer.