Equilateral Triangle Calculator

Calculate an equilateral triangle. This is the simplest regular polygon (a polygon with equal sides and angles). Enter one of the known values. Then click calculate.

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Enter one of the known values of an equilateral triangle

Side length (a=b=c)
Height (h)
Perimeter (p)
Square (S)
The radius of the circumscribed circle (R)
Radius of the inscribed circle (r)

Formulas

h = √3/2 * a
р = 3 * а
S = a2 * √3 / 4
R = √3 / 3 * a
r = √3 / 6 * a
All angles are equal to each other and equal to 60°

The side length, height, perimeter and radius have the same unit of measurement (for example, a centimeter), the area has the same unit of measurement squared (for example, a square centimeter).

Perimeter P, area A
Heights ha, hb, hc
Circumscribed circle, inscribed circle
Angles and bisectors
The middle of the side
Perpendicular bisector