Back
Diagonals on a Cube
Easy
Created: November 2, 2025
Two diagonal lines are drawn on a cube. What is the angle between these two lines?
Solution
60°.
Notice that if we connect a 3rd line between the ends of the other 2 lines, we form an equilateral triangle with angles of 60° on all sides.
Try These Next
Medium
The Buried Cable
The enemy has run a communication cable in a straight line somewhere beneath a square plot of land, 1 km on each side. The cable's exact position and direction...
Easy
One Less Than a Prime Squared
Show that p^2-1 is always a multiple of 24 if p is a prime that is bigger than 3.
Easy
8 Queens
Can you place 8 queens on a chessboard so that no queen can capture any other queen? Recall that a queen can move any number of squares horizontally,...