Drawing using Array in AutoCAD

1. Create a polyarc using PLINE command as shown below. I have used 1st included angle as 180 and the rest two 45.

2. Use polar array option in ARRAY Command, select the complete object.

3. Select the bottom endpoint of the arc as the centre point

4. Select no. of items as required, I have taken 72.

5. The Angle to fill is 360.

And the final output will be as shown below.