Combining Two Solids

When two 3D shapes are joined to form a new object, it's called a combined solid.

How do we calculate?

• Volume → Add volumes of both solids.

• Surface Area → Only add the outer parts that are visible.

Important:

• The surface where they are joined is hidden, so we don't include it.

Example:

An ice cream cone has:

• A cone (top part)

• A cylinder (bottom cone holder)

👉 Total Volume = Volume of cone + Volume of cylinder
👉 Surface Area = Outer cone + Outer cylinder + Bottom base (but NOT the circle between them)