Surf the wave

A white triangle in a blue square. What is it’s top angle α?

Scroll down for a solution to this problem.


The angle α is 45°.

Solution by Dr Rick.

This solution makes use of the RHS theorem.

Visual solution

Solution without words by David Andriana.


A good spot for surfing
At the sea where it’s so tempting
To surf is not easy
For perfect waves a champion is searching
He dreams from waves and from riding
He glides on the board
As sharp as a sword
It gives good feelings
On the top of the waves
He’s on the top of the world


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