Calculate Diagonals Angles

Calculator for the angles of the diagonals in a rectangle. The length of the diagonal is calculated with the theorem of Pythagoras. The angles in the corners of the rectangle are calculated with the law of cosines in a triangle with the sides a, b and d. The angles between the diagonals result from the angular sum in a triangle of 180 degrees and the values of the corner angles. Please enter length and width, the diagonal length and the angles will be calculated.

Diagonals angles

Length a:
Width b:
Diagonal d:
Corner angle opposite a, α: °
Corner angle opposite b, β: °
Diagonal angle top/bottom, γ: °
Diagonal angle left/right, δ: °
Round to    decimal places.


Diagonal, d = √ a² + b²

Angle alpha, α = acos[ ( b² + d² - a² ) / 2bd ]

Angle beta, β = acos[ ( a² + d² - b² ) / 2ad ]

Angle gamma, γ = 180° - 2β

Angle delta, δ = 180° - 2α

Here you can convert degrees into radian.