Embedded Images

What you need to understand

A shape is embedded when all of its sides are drawn. It is not enough for most of them to be there - one missing side means the shape is not in the figure.

The sides of the hidden shape are drawn as part of a larger pattern of lines, so the lines run past the corners of the shape and cross each other. What you are looking for is a run of lines that closes up into the shape.

The hidden shape keeps its direction and its size. It is not turned or made bigger, so a shape that only matches when you turn it is not the answer.

Each of the other three shapes is missing one side only. That is what makes the question worth doing: the wrong shapes are nearly complete.

The sides of the figure that belong to no shape are there to make the drawing harder to read, and they can be ignored.

A side of the shape does not have to be a single drawn line. Two shorter lines meeting end to end along the same line still draw that side.

How to work through these questions

Look at the four shapes first. Note the sides of each one - its angles and the lengths of its sides - and put the figure aside for a moment.

Take one shape and follow its outline through the figure. Start at the longest side, because a long side is the easiest to find among the lines.

Having found one side, look at where it meets the next side. The next side has to start at that corner and run in the direction the shape says.

If the next side is there, carry on round the shape. If it is not, the shape is out - go straight to the next shape rather than going back over the one you have just rejected.

Claim a shape only when you have followed all of its sides back to the starting corner and every one of them was drawn.

Mistakes that cost marks

Accepting a shape because most of its sides are there. Each wrong shape is missing exactly one side, so it will look right until you reach the side that is missing.
Being satisfied with a side that is nearly in the right place but drawn at a different angle.
Matching a shape that is only there if you turn it. The shapes are not rotated.
Matching a shape of a different size when the option is drawn larger or smaller than the shape in the figure.
Stopping as soon as you find a shape that seems to fit, without checking that no other shape fits as well.
Reading a line as part of the shape when the line is only crossing it.

Worked example

A figure is drawn from a dozen straight lines, and four shapes are offered - a triangle, a quadrilateral, a pentagon and another quadrilateral. Exactly one of the four is complete in the figure.

Read the four shapes and note the longest side of each.
Take the triangle first. Find a line in the figure running the same way and the same length as its longest side.
From the corner where that line ends, the second side of the triangle has to run off at the angle the triangle shows. Look for a line running that way from that corner.
If there is no such line, the triangle is not embedded, and the two sides you have found are two lines of the figure that happen to run that way.
Do the same for the remaining shapes, in each case following the sides round from the longest one.
The shape that comes back to its starting corner with every side drawn is the answer.

Answer: The shape whose every side, taken in turn, lies along a line of the figure.

Practice questions with answers

A few Embedded Images questions with the full solution shown, so you can see how the method is applied before you attempt the timed set.

Question 1

One of the four shapes given below is hidden in the lines of this figure. Which shape is it?

Answer: Option D — with explanation

The figure is a set of straight lines, and one of the four shapes is formed exactly by some of them. Take the shapes one at a time and follow each side round. The embedded shape has every side lying along a line that is drawn; in each of the others one side is missing from the figure, so that shape is nowhere complete in it. Common mistakes - in this shape the first side is not drawn anywhere in the figure - in this shape the first side is not drawn anywhere in the figure - in this shape the second side is not drawn anywhere in the figure

Question 2

One of the four shapes given below is hidden in the lines of this figure. Which shape is it?

Answer: Option B — with explanation

The figure is a set of straight lines, and one of the four shapes is formed exactly by some of them. Take the shapes one at a time and follow each side round. The embedded shape has every side lying along a line that is drawn; in each of the others one side is missing from the figure, so that shape is nowhere complete in it. Common mistakes - in this shape the fourth side is not drawn anywhere in the figure - in this shape the first side is not drawn anywhere in the figure - in this shape the fourth side is not drawn anywhere in the figure

Question 3

Which of the four shapes below is embedded in this figure?

Answer: Option C — with explanation

The figure is a set of straight lines, and one of the four shapes is formed exactly by some of them. Take the shapes one at a time and follow each side round. The embedded shape has every side lying along a line that is drawn; in each of the others one side is missing from the figure, so that shape is nowhere complete in it. Common mistakes - in this shape the second side is not drawn anywhere in the figure - in this shape the first side is not drawn anywhere in the figure - in this shape the second side is not drawn anywhere in the figure

Question 4

The lines in this figure form one of the shapes below, complete. Which one?

Answer: Option B — with explanation

The figure is a set of straight lines, and one of the four shapes is formed exactly by some of them. Take the shapes one at a time and follow each side round. The embedded shape has every side lying along a line that is drawn; in each of the others one side is missing from the figure, so that shape is nowhere complete in it. Common mistakes - in this shape the third side is not drawn anywhere in the figure - in this shape the fourth side is not drawn anywhere in the figure - in this shape the second side is not drawn anywhere in the figure

Question 5

The lines in this figure form one of the shapes below, complete. Which one?

Answer: Option A — with explanation

The figure is a set of straight lines, and one of the four shapes is formed exactly by some of them. Take the shapes one at a time and follow each side round. The embedded shape has every side lying along a line that is drawn; in each of the others one side is missing from the figure, so that shape is nowhere complete in it. Common mistakes - in this shape the second side is not drawn anywhere in the figure - in this shape the third side is not drawn anywhere in the figure - in this shape the first side is not drawn anywhere in the figure

Frequently asked questions

Do I need to check every shape?

Yes, but only until a side fails. In each wrong shape one side is missing, so most of the work is following the shape round until you reach the side that is not there. Once a side fails the shape is out and you move on.

Can the hidden shape be turned round?

No. It is the same way up and the same size in the figure as it is in the option. A shape that only lines up when you turn it is not the embedded one.

The figure is a tangle of lines. Where should I start?

With the longest side of the shape you are testing. Long lines are much easier to pick out of a crowded figure than short ones, and once you have one side you have a corner to work from.

What if a side of the shape is drawn in two pieces?

That still counts. The line is there whether it is drawn as one stroke or as two - what matters is that the side is covered from corner to corner.