What is the least possible number of piece which have at most one colour on them?

The outer design is reversed laterally from first figure to second figure and the wavy lines of the inner design get thick.

NA

NA

From first figure to second figure entire design rotates through 45°.

3 lies opposite.
lies opposite W.
1 lies opposite.
In option (2) 3 is on the adjacent face of dot.
In option (3) is on the adjacent face of W.
In option (4) is on the top and hence the positions of dot () and W are not correct.

In the given cut out pieces there are four right angled triangles and one obtuse angled triangle. If we observe carefully we find that Answer figure (1) Contains four right angled triangles and one obtuse angled triangle. Therefore, the Answer figure (1) can be formed from the given cut out pieces.

On the basis of given figures in above question , we can see that
In each subsequent figure all the designs move one step in anticlockwise direction.
Hence , figure ( 4 ) will come on the place of ? from answer figures .

Every time one line segment joints the figure.

On the basis of given figures in above question , we can see that
In the subsequent figures the angle between the two sides is increasing by 30°.
Thus , figure ( 2 ) will come on the place of ? in question figure .As shown in answer figures .

According to above given question figures , we can say that
In each subsequent figure the central design rotates through 900 clockwise while other four designs move one step in anti-clockwise direction
Hence , figure ( 4 ) will come on the place of ? from answer figures .