Unit 5: Geometry - 9C

• Wiskunde
• Middelbare school
• havo
• Leerjaar 1

9C: 2-D representations of 3-D shapes

Class: T1A

Unit 5

Solids

- A three-dimensional (3-D) shape

Solids

- A three-dimensional (3-D) shape

- Width, length, height...

Solids

Solids

- A three-dimensional (3-D) shape

- Width, length, height...

- What solids have a square as a base?

Solids

- What solids have a square as a base?

Solids

- What solids have a square as a base?

Solids

- What solids have a square as a base?

Cube

Solids

- What solids have a square as a base?

Cube

Box

Solids

- What solids have a square as a base?

Cube

Box

Square-based

pyramid

Solids

- What solids have a square as a base?

Cube

Box

Square-based

pyramid

Triangular

prism

Solids

- What solids have a triangle as a base?

Solids

- What solids have a triangle as a base?

Solids

- What solids have a triangle as a base?

Triangular-based

pyramid

Solids

- What solids have a triangle as a base?

Triangular-based

pyramid

Triangular prism

Solids

- What solids have a circle as a base?

Solids

- What solids have a circle as a base?

Solids

- What solids have a circle as a base?

Circular-based pyramid / cone

Solids

- What solids have a circle as a base?

Circular-based pyramid / Cone

Circular prism / Cylinder

Cross-section

- A cross-section of a solid is literally a slice of a solid. For example...

Cross-section

- A cross-section of a solid is literally a slice of a solid. For example...

Cross-section prisms

- Not all solids have a constant cross-section.

- Prisms do have a constant cross-section.

- For prisms, the cross-section names the prism.

Is a box always a prism?

1. Yes
2. No

Cross-section prisms

- If you take a slice from a box, you will get a rectangle, so the cross-section is a rectangle.

- This means a box is also called a rectangular prism.

Does a pyramid have a constant cross-section?

1. Yes
2. No

Bases pyramids

- Because pyramids don't have a constant cross-section we use their base to name them.

- For pyramids, the base thus names the pyramid.

Bases pyramids

- For pyramids, the base names the pyramid.

- What's this solid called?

Bases pyramids

- For pyramids, the base names the pyramid.

- What's this solid called?

Pentagonal based pyramid

Face, Edge, Vertex

Face, Edge, Vertex

 - A face is a flat surface of a solid.

Face, Edge, Vertex

 - A face is a flat surface of a solid.

 - An edge is the line where two faces meet.

Face, Edge, Vertex

 - A face is a flat surface of a solid.

 - An edge is the line where two faces meet.

 - A vertex is a point at which three or more edges meet.

Face, Edge, Vertex

 - A cube has 6 faces, 8 vertices and 12 edges

How many faces does a box have?

1. 2
2. 4
3. 6
4. 8

How many vertices does a square-based pyramid have?

1. 3
2. 4
3. 5
4. 6

Face, Edge, Vertex

 - A square-based pyramid has 5 faces, 8 edges  and 5 vertices

How many edges does a triangular-based pyramid have?

1. 4
2. 6
3. 8
4. 12

Face, Edge, Vertex

 - A triangular-based pyramid has 4 faces, 6 edges  and 4 vertices

Make:

9C: 2-D representations of 3-D shapes

 - Questions 1, 2 and 3

Hand in for feedback! (Optional)

 Homework: