Draw a line segment `A B` and by ruler and compasses, obtain a line segment of length `3/4(A B)`

Explanation

Steps of construction:

1. Draw a line segment AB.

2. Draw a ray AX making an acute angle with AB and mark 4 equal parts at A1,A2,A3 and A4.
3. Join A4B.

4. From A3, draw a line parallel to A4B which meets AB at C.

Here, C is the required point and `AC = 3/4(AB)`.