- Plastic is a kind of material
- Glass is a kind of material
- Therefore, glass and plastic are two materials

- Glass and plastic are two materials
- Fiberglass is made of glass and plastic
- So, fiberglass is made of at least two materials

- Fiberglass is made of at least two materials
- Composite materials are made of two more more materials
- Hence, fiberglass is a kind of composite materials

Hence, fiberglass is a kind of composite materials
Question
Which of these is a composite material?

Context
- Fiberglass is made of glass and plastic 
- Composite materials are made of two more more materials 
- Plastic is a kind of material 
- Glass is a kind of material