MathDB

2

Part of 1972 USAMO

Problems(1)

Isoceles Tetrahedron

Source: 1972 USAMO Problem 2

3/6/2010
A given tetrahedron ABCD ABCD is isoceles, that is, AB\equal{}CD, AC\equal{}BD, AD\equal{}BC. Show that the faces of the tetrahedron are acute-angled triangles.
geometry3D geometrytetrahedroninequalitiesparallelogramtriangle inequality