| Triangle Calculator |
Note: Calculation can be based on any 3 items above. If no results after click "Calculate" button, then the data provided is impossible to shape a triangle.
| Calculation can be based on the coordinates of the three points of the triangle: |
| X | Y | ||
| A : | |||
| B : | |||
| C : |
Note: If no results after filling in all coordinates, then the data provided is impossible to shape a triangle.
Results:
| Area: | |||||||
| Perimeter: | |||||||
| Circumscribed Circle Radius: | |||||||
| Inscribed Circle Radius: | |||||||
| Height of a: | |||||||
| Height of b: | |||||||
| Height of c: | |||||||
| Angle Bisector of a: | |||||||
| Angle Bisector of b: | |||||||
| Angle Bisector of c: | |||||||
| Median of a: | |||||||
| Median of b: | |||||||
| Median of c: | |||||||
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Triangle has three sides and three angles. The sum length of any two sides is longer than the length of the other side.
All angles of a triangle always add up to 180 ̊C. |
Triangle Formulas
| Law of Cosines |
a2 = b2 + c2 - 2 × b × c × CosA; b2 = a2 + c2 - 2 × a × c × CosB; c2 = b2 + a2 - 2 × b × a × CosC; |
| Area |
a × b × Sin(C) / 2 or c × b × Sin(A) / 2 or a × c × Sin(B) / 2 |
| Angle Bisector of Side a | 2 × b × c × Cos(A/2) / (b + c) |
| Angle Bisector of Side b | 2 × a × c × Cos(B/2) / (a + c) |
| Angle Bisector of Side c | 2 × a × b × Cos(C/2) / (a + b) |
| Median of Side a ( ma ) | ma2 = (2 * b2 + 2 * c2 - a2) / 4 |
| Median of Side b ( mb ) | mb2 = (2 * a2 + 2 * c2 - b2) / 4 |
| Median of Side c ( mc ) | mc2 = (2 * a2 + 2 * b2 - c2) / 4 |
| Circumscribed Circle Radius |
a / ( 2 * sin (A)) or b / ( 2 * sin (B)) or c / ( 2 * sin (C)) |
| Inscribed Circle Radius |
a × Sin(C/2) × Sin(B/2) / Cos (A/2) or b × Sin(A/2) × Sin(C/2) / Cos (B/2) or c × Sin(A/2) × Sin(B/2) / Cos (C/2) |
Triangle Types
All three angles of a triangle always add up to 180 ̊C. Triangle has three types based on its three angles.
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Obtuse Triangle has an angle > 90 ̊C. |
Right Triangle has an angle = 90 ̊C. |
Acute Triangle all angles < 90 ̊C. |
Triangle has three types based on the equality of its three sides.
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Equilateral Triangle all sides are equal, all angles are 60 ̊C. |
Isosceles Triangle two equal sides. |
Scalene Triangle no equal sides and angles. |

















