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Distance Formula Calculator
Calculate the straight-line distance between two points on a plane with the distance formula.
Triangle Calculator
Solve any triangle from three sides or two sides and the angle between them: angles, area, perimeter and type.
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How to use this calculator
Enter your values after choosing the type of calculation in the tabs. The result updates as you type; press Calculate to confirm and jump to the result on mobile. Use Share to send the calculator with your result.
Formulas used
Law of cosines: c² = a² + b² − 2ab·cos(C)
Heron's formula: Area = √(s(s − a)(s − b)(s − c)), s = (a + b + c) ÷ 2
Angles sum: A + B + C = 180°
Triangle inequality: each side must be shorter than the sum of the other two. Example: sides 5, 6, 7 → s = 9, area = √(9·4·3·2) ≈ 14.697; angles ≈ 44.42°, 57.12°, 78.46°.
Frequently asked questions
What is a scalene triangle?
A triangle with three sides of different lengths (and three different angles).
Can a triangle have two right angles?
No, the angles must add to 180°.
About this tool
- Written by
- [Author: to be assigned]
- Reviewed by
- Formula tests passed · human review pending
- Last updated
- 31 Oct 2026
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