# Guess the other shape

Each solid shape is somehow related to the shape below it.

Find this relationship and the correct shape for the last one.

Edit: simplified second shape from left to a polygon

C

Explanation

Read the circles/bars from front to back based on the way they overlap each other, they form binary numbers.
For example, the circles/bars represent, from left to right: 10, 110, 11, 101, 011, 00.
This matches the number of points (or convex corners) on the shape above. (from the third shape we can tell that concave corners are to be ignored)
The last shape has 5 points, so we want 101, which is C.

Excellent puzzle!

• Well done! It should be more fun if there was another 1,0,1 option that was not in right order.
– Rafe
Commented Jan 5, 2015 at 12:25
• Could you explain the number of points part?
– TMH
Commented Jan 5, 2015 at 12:33
• @Tom Hart: If the shape were to hit you in the face, which parts would poke your eye out? Those are the points. I edited to call them convex corners, if that helps. Commented Jan 5, 2015 at 12:37

by Elimination i choose

C.

All the patterns with a triangle/sharp shape have 2 rods.

the last pattern has a triangle shape too. and there is only one answer with 2 rods.

• That was not the answer I have expected. Also no description for the relationship. so the picture is now edited (the triangle from second shape from left is removed) thanks
– Rafe
Commented Jan 5, 2015 at 10:10

B

Following the logic that:

IFF the (silhouet of the) lower shape has rotational symmetry, the upper shape has rotational symmetry (and vice versa)

• what do you mean by rotational symmetry? do you mean the same shape if rotate it 180 degrees?
– Rafe
Commented Jan 6, 2015 at 12:42
• @Rafe In general less than 360 (in these cases it would be either 180 or 120) Commented Jan 6, 2015 at 12:46
• hmmm... that's interesting. what about the circle? the shape below it has not rotational symmetry!
– Rafe
Commented Jan 6, 2015 at 12:51
• @Rafe That is why I only looked at the silhouette. Commented Jan 6, 2015 at 13:33
• Oh... That's right! :-)
– Rafe
Commented Jan 6, 2015 at 13:58

C

Since by eliminating the other options.

Since its doesn't have a round geometry whatsoever, A,D eliminated.
B resembles to the 1st figure, therefore C would be a fair assumption.