Summary We prove the next generalization of the Steiner-Lehmus theorem: if two equal cevians intersect with each other on the angle bisector of the third triangle vertex, then the triangle is ...

The Mathematical Gazette is the original journal of the Mathematical Association and it is now over a century old. Its readership is a mixture of school teachers, college and university lecturers, ...

In the diagram below, AB is the chord of a circle with centre O. OM is perpendicular to AB (meet at a right angle). Look at triangles OAM and OBM. The hypotenuses (OA and OB) are the same, as they are ...

Interior angles in a triangle add up to 180˚. Triangles close triangleA polygon with three straight sides. have three sides, therefore they have three angles. Interior angles in a triangle sum to a ...

Angle Bisector, BD, is drawn within Triangle ΔADC, bisecting ےADC. Segment AB has a length of x. Segment BC has a length of x − 2. Segment CD has a length of x + 3. Segment AD has a length of x + 6.