Open prb40-1.dwg and save it as prb40-2.dwg. Create a 3D face for a concrete pad under the shed. The pad measures 18'× 20' and extends beyond the shed walls evenly (5') on all sides. When you are finished, the model should look similar to the one in Fig. 40-5.
![2348_b50905be-4fec-489c-9ea8-160ba92bf61b.png](https://secure.tutorsglobe.com/CMSImages/2348_b50905be-4fec-489c-9ea8-160ba92bf61b.png)