Computes angle between two segments sharing a point.

Computes angle between two segments of a triangle using law of cosines.

cosine.ang(l, r, o)

Arguments

l

Numeric; length of segment to the left

r

Numeric; length of segment to the right

o

Numeric; length of opposite segment

Value

A single value of the angle in radians

Examples

#a right triangle
L=3
R=3
O=sqrt(L^2+R^2)
cosine.ang(L,R,O)
#> [1] 1.570796