Triangle Area Calculator

What is the Triangle Area Calculator?

Calculate the area of a triangle from its base and height. Triangle area from base and height is one of the most common geometry calculations, used for gables, sails and land plots.

How to use the Triangle Area Calculator

1. Enter your base, your height.
2. Results update automatically as you type; you can also press Calculate.
3. Read the output: area.
4. Use the 📊 chart to see the result visually, then copy or share it.

Formula and method

Worked example

With base = 10, height = 6, the Triangle Area Calculator returns area: 30.

Where the Triangle Area Calculator helps in real life

You are painting the triangular gable end of a house, 8 m wide and 3 m tall. The area of 12 m² tells you how much paint to buy.

A sailmaker estimates fabric for a triangular sail from its foot length and height.

Common mistakes to avoid

• Using a slanted side as the height.
• Forgetting to halve base times height.
• Mixing units between base and height.
• Measuring height to a point outside the base without adjusting.

💡 Practical tip: Triangle area is always half of base times height, whatever the triangle’s shape.

Tips for better results

• Measure height perpendicular to the base.
• Use Heron’s formula when you only know three sides.
• Add extra for overlaps when buying materials.

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