Triangle from given side a, b and angle alpha, calculator and formula

With this calculator, the side length a, the angles β and γ, the area, height and the perimeter of a triangle is calculated from the side lengths a,b and the angle α

Enter the 3 values, then click on the 'Calculate' button.

Triangle calculator

Input

Angle α

Side length a

Side length b

Decimal places

Resultat

Side c

Angle β

Angle γ

Height

Perimeter

Area

Formulas for calculation

Angle β

\(\displaystyle β = asin\left(\frac{sin(α)}{a}·b \right)\)

Angle γ

\(\displaystyle γ = 180-α-β\)

Side c

\(\displaystyle c = \frac{a}{sin(α)}·sin(γ) \)

Perimeter

\(\displaystyle P = a+b+c\)

Height

\(\displaystyle h = b· sin(γ)\)

Area

\(\displaystyle A = \frac{a·h}{2}\)

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