CATIA V5 Fundamentals-Basic Features

http://www.cadfamily.com/downinfo/300454.html
The engine support must meet the following design intent requirements:There must be no internal loops created in a sketch.• Each element on this model must be created as separate features.

By creating each element separately, future modifications will be easier.The four center holes must be created as one feature.• Typically, one hole is created first, then patterned to create the other three holes. Since the requirement is to have them created as one feature, a pocket will need to be used.The fillets and the chamfer may need to be removed in downstream applications.• The fillets and the chamfer cannot be created within the sketched profile; they must be created as separate features