Rectangles

What is Rectangles?

Rectangles is a logic puzzle about cutting up a grid. A few of the squares hold numbers, and you divide the whole grid along its lines into rectangles, so that every rectangle holds exactly one number and has exactly as many squares as that number. A 6 can become a rectangle of 2 by 3, 3 by 2, 1 by 6 or 6 by 1; the numbers around it decide which. Around the world the puzzle is also known as Shikaku.

Every board has exactly one answer, and it can always be reached by reasoning, never by guessing. Boards come in three sizes, 7 by 7, 10 by 10 and 13 by 13, and a new board, the same for everyone, arrives every day.

How to play

Put your finger on one corner of the rectangle you want, drag to the opposite corner and let go.

• Drawing. While your finger is down you see the rectangle and its size under the board. It fills with its number's colour once it fits that number exactly. A rectangle drawn over others replaces them, and letting go well off the board draws nothing.
• Taking away. Tap a rectangle to take it away. A lone 1 is its own rectangle: tap it to give it its square.
• Red rectangles. A rectangle turns red when it holds no number, more than one, or a different number of squares than its number, and the line under the board says which.
• Undo. Undo takes back your last change, and puts back any rectangles it replaced.
• Score. Your score is the time to cut the whole board, plus 30 seconds for every hint. Every board size has its own leaderboard.

Strategy tips

1. Start where there is no choice. A large number in a corner, or a number hemmed in by its neighbours, often fits only one way. Draw those first.
2. Look for lonely squares. A square that only one number can reach belongs to that number, so its rectangle must cover it. Corners and squares walled in by rectangles already drawn are the usual ones.
3. Use the overlap. When every way a number can go covers the same squares, those squares are taken, and no other number can use them.
4. Mind the primes. A 2, 3, 5, 7, 11 or 13 can only make a straight strip, one square wide, so it has far fewer shapes than a 6 or a 12.
5. Leave nothing stranded. A rectangle that would leave some square out of reach of every number, or wall off a corner whose numbers cannot fill it exactly, is wrong. On the large boards, follow a choice a few rectangles ahead to see where it leads.

FAQ

Is Rectangles free to play?

Yes. Like every game on Play, it runs free in your browser, with no download and no account needed.

Does every square have to be in a rectangle?

Yes. The rectangles cover the whole grid, with no gaps and no overlaps, and every one of them holds exactly one number.

What does a hint do?

It takes away a rectangle that is not part of the answer first, if there is one; otherwise it draws the next rectangle that follows by logic from the board, and the line under the board says why. Each hint adds 30 seconds to your time.

What is today's board?

Every day everyone plays the same medium 10 by 10 board, so times compare directly on the leaderboard.

How is my score counted?

Your score is the time from the first look at the board to the last rectangle that completes it, plus 30 seconds for every hint. Lower is better.