The clue is on top of the elevator door. As you can see Triangle + Square = 7. Count the sides of the shape. Triangle = 3 sides, square = 4 sides, so 3 + 4 = 7.
You must count the sides of every shape on the door. Start from the bottom left square and go clockwise. The answer will be:
- Square = 4
- Triangle = 3
- Square = 4
- Triangle = 3
- Circle = 0
- Arrow (square and triangle) = 7
- Square = 4
- Tap on the keypad on the left to zoom in. Key in 4,3,4,3,0,7,4.
Elevator opens. Welcome to level 21.
