MathDB

26

Part of 1980 AMC 12/AHSME

Problems(1)

Tetrahedron

Source:

1/1/2006
Four balls of radius 1 are mutually tangent, three resting on the floor and the fourth resting on the others. A tetrahedron, each of whose edges have length ss, is circumscribed around the balls. Then ss equals (A) 42(B) 43(C) 26(D) 1+26(E) 2+26\text{(A)} \ 4\sqrt 2 \qquad \text{(B)} \ 4\sqrt 3 \qquad \text{(C)} \ 2\sqrt 6 \qquad \text{(D)} \ 1+2\sqrt 6 \qquad \text{(E)} \ 2+2\sqrt 6
geometry3D geometrytetrahedron