Combining parts to make an square

Question

In the following picture, if one puts some of the shapes A, B, C, D, and E together, they can make a square. Then which shapes would be redundant?

1. Only A
2. Only D
3. Only E
4. A and D

Can you construct the square and show it in a picture? I found it hard which part should be placed beside which part.

Source:Iranian Ph.D. Entrance exam 2017

Answer 1

You can fit them together like this (diagram not perfectly to scale):

which uses

all except D.

(Highly sophisticated mathematical solution technique: print on paper, cut out the shapes, push them around and see what happens.)