How do you calculate the area of a triangle?

The standard formula to calculate the area of a triangle is to multiply the base by the height, and then divide by 2. (Formula: (Base × Height) ÷ 2).

Can you solve a triangle if you only have 3 angles?

No. Knowing all three angles (AAA) only tells you the shape of the triangle, not its size. To calculate the exact lengths of the sides, the perimeter, or the area, you must know at least one side length.

What does SSS, SAS, and ASA mean in geometry?

These are abbreviations for the known parts of a triangle. SSS stands for Side-Side-Side. SAS stands for Side-Angle-Side. ASA stands for Angle-Side-Angle. Our free triangle calculator can solve your math problem using any of these three methods.

Triangle Calculator

1. Advanced Triangle Solver

What do you know about the triangle?

Side a

Side b

Side c

Side a

Angle C (°)

Side b

Angle A (°)

Side c

Angle B (°)

Triangle Properties

Side a

Angle A

Side b

Angle B

Side c

Angle C

Area

Perimeter

2. Calculate Area (Base & Height)

Use this if you only need the total area. Formula: (Base × Height) ÷ 2

Base

Height

How to Use This Triangle Calculator

Whether you are a student working on geometry homework or a DIYer planning a project, our free Triangle Calculator takes the heavy lifting out of complex math. We offer two ways to calculate your triangle's dimensions.

1. The Advanced Triangle Solver

Use this tool when you know some of the sides or angles, but need to find the rest. Simply select what you currently know from the dropdown menu:

3 Sides (SSS): You know the length of all three sides.
2 Sides & 1 Angle (SAS): You know the length of two sides and the angle directly between them.
2 Angles & 1 Side (ASA): You know two angles and the length of the side connecting them.

Note: You cannot calculate a triangle's size based solely on 3 angles (AAA), as angles only determine a triangle's shape, not its exact measurements.

2. Calculate Basic Area

If you don't need to know the angles or perimeter, use the Basic Area Calculator at the bottom. Just input the base and the height of the triangle to instantly find the total area.

The Math Behind the Tool: This calculator uses standard geometry formulas including the Pythagorean theorem (a² + b² = c²), the Law of Sines, the Law of Cosines, and Heron's formula to ensure perfect accuracy.

Triangle Calculator

1. Advanced Triangle Solver

2. Calculate Area (Base & Height)

How to Use This Triangle Calculator

1. The Advanced Triangle Solver

2. Calculate Basic Area

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