Try this beautiful problem from Math Olympiad Hanoi, 2018 based on Cubes and Rectangles.
Find the number of rectangles can be formed by the vertices of a cube.
Geometry
Permutation
Combination
Answer: 12.
Math Olympiad Hanoi 2018
Geometry Vol I to IV by Hall and Stevens
There are 6 squares on 6 faces on the cube.
There are 4 diagonals of the cube that have the same length
and pass through the center of the cube. Every two diagonals intersect at the midpoint and form a rectangle.
Then there are 6+ $(\frac{4!}{2!2!})$ =12 rectangles.

In 2025, 8 students from Cheenta Academy cracked the prestigious Regional Math Olympiad. In this post, we will share some of their success stories and learning strategies. The Regional Mathematics Olympiad (RMO) and the Indian National Mathematics Olympiad (INMO) are two most important mathematics contests in India.These two contests are for the students who are […]

Cheenta Academy proudly celebrates the success of 27 current and former students who qualified for the Indian Olympiad Qualifier in Mathematics (IOQM) 2025, advancing to the next stage — RMO. This accomplishment highlights their perseverance and Cheenta’s ongoing mission to nurture mathematical excellence and research-oriented learning.

Cheenta students shine at the Purple Comet Math Meet 2025 organized by Titu Andreescu and Jonathan Kanewith top national and global ranks.

Celebrate the success of Cheenta students in the Stanford Math Tournament. The Unified Vectors team achieved Top 20 in the Team Round.