Steps of construction:

1. Draw an angle ∠XAY = 50°

2. Taking radius as 5 cm, draw arcs on lines AX and AY such that AX is intersected by arc on B and AY is intersected by arc on D

3. From B and D draw arcs of 5 cm, which intersect at C.

4. Join BC and CD to get the required rhombus

For Incircle

5. Join AC and BD, such that AC and BD intersect each other at O.

6. Draw OP perpendicular to any of the sides, [we have chosen BC]

7. Taking O as center, and OP as radius draw the required incircle.