CAT 2004 — QA Question 33
Basics of Mensuration/PrismEasy
If the lengths of diagonals DF, AG and CE of the cube shown in the adjoining figure are equal to the three sides of a triangle, then the radius of the circle circumscribing that triangle will be _______.

Answer & solution
Correct answer: equal to the side of the cube
equal to the side of the cube
- B
times the side of the cube
- C
times the side of the cube
- D
impossible to find from the given information
Solution
Let the side of the cube be a units.
DF, AG and CE are body diagonals each of length a√3 units.
∴ Circumradius of the equilateral triangle = = a units
∴ Circumradius = side of cube
Hence, option (a).