Ortsbogen theorem

From Wikipedia, the free encyclopedia

In geometry, for any line segment AB and angle θ < π, the locus of points C on one side of line AB such that angle ACB equals θ is an arc of a circle. Points outside this arc form sharper angles than θ, while points within this arc form wider angles.^[1]

In the Swiss school curriculum this arc is known as an "Ortsbogen" and the theorem that the locus has this shape is known as the Ortsbogen theorem.^{[citation needed]}