This document discusses cubes including their parts, surface area, and volume. It defines a cube as a solid geometry with six equal square faces and eight vertices. The parts of a cube are identified as the six faces, twelve edges, and eight vertices. Formulas are provided to calculate the surface area of a cube as 6s^2 and the volume of a cube as s^3, where s is the length of an edge. Examples are given to practice calculating surface areas and volumes when given the length of an edge or to determine the edge length when given the surface area or volume. Students are assigned homework problems applying these concepts.

1. CUBES

2. CUBES
Parts of Cube
Surface Area of A Cube
Volume of A Cube

3. What is
cube?
Cube is a solid geometry with six
congruent square faces or a regular
hexagon.
A cube is a region space formed by six
identical square faces joined along
their edges.
The cube can also be called a regular
hexahedron.

4. Class
Activity
“Identify
Your Cube”
Look and identify your own cube!
After that you must rewrite this table and
fill the blank on your book by yourself.
You have 2 minutes to do this activity
PartsThe Cube Sum
Face …
Edge …
Vertex …
Face Diagonals …
Space Diagonals …

5. Bagian Kubus
(Parts of A Cube)

6. Face (Sisi)
Also called facets or sides. A cube
has six faces which are all squares,
so each face has four equal side
and all four interior angles are
right angels.

7. Edge (Rusuk)
A line segment formed where two
faces meet. A cube has twelve
edges.
Because all faces are squares and
congruent to each other so all of
edges are the same length.

8. Vertex (Titik Sudut)
A point formed where three edges
meet. A cube has eight vertices.

9. Face Diagonals (Diagonal Bidang)
Face diagonals are line segment linking the
opposite corners of a face.
Each faces has two , for a total of twelve in
the cube. The length of the face diagonals is
given by formula :
𝒅 = 𝒔 𝟐
(using PythagorasTheorem)
Where “s” is the length of one edge. Since the
faces are squares, this is the same as the
diagonal square.

10. Space Diagonals (Diagonal Ruang)
Space diagonals are line segments
linking the opposite corners of cube
cutting through its interior.
A cube has four space diagonals. The
length of the space diagonals is given
by formula :
𝒅 = 𝒔 𝟑
(using PythagorasTheorem)
Where “s” is the length of one edge.

11. Exercise 1. If the edge is 10 cm, how length does
the face diagonals?
2. If the edge is 15 cm, how length does
the space diagonals?
3. Father will make iron model of cube.
If the edge is 8 cm, how cm does father
need the iron?

12. Surface
Area Of
A Cube
• Definition:
The number of square units that
will exactly cover the surface of a
cube.
• How to find the surface area of a
cube?

13. Look at the picture!

14. The total surface area is therefore
six times the area of one face or as a
formula :
Surface Area = 6s2
Where “s” is the length of any edge
of the cube.

15. How you find the edge if you know
the surface area?

16. Exercise 1. The edge of cube is 4 cm.
How cm2 does the surface area?
2. If the surface area of cube is 150
cm2, how cm does length of the
edge?
3. A cube has base perimeter 52
cm. How cm2 does the surface
area that cube?

17. Volume of
A Cube
• Definition
The number of cubic units that will
exactly fill a cube.
• How to find the volume of cube?

18. The volume of a cube is found by
multiplying the length of any edge by
itself twice.
Or as a formula :
𝑽 = 𝒔 𝟑
(s to the power 3)
Where “s” is the length of any edge of
the cube.

19. How you find the edge if you know
the volume?

20. Exercise 1. Find the volume of cube if the edges
6 cm!
2. If the volume of cube is 512 cm3,
how cm does length the edge?
3. How cm3 does the volume of cube
if the surface area is 600 cm2 ?

21. Conclusion
The formulas

22. Individual Test
1. I have cable which the length is 1 meters
and I will make a cube. If the edge is 8
cm, how cm the remainder do I have?
2. If the face diagonal is 𝟗 𝟐 cm, how cm3
the volume of that cube?
3. If the cube has volume 343 cm3 , so how
cm2 does the surface area of that cube?
4. If the cube has the volume 216 cm3, how
cm length does the space diagonal?
5. The edge of two cube are 3 cm and 9 cm.
Find volume ratio from two cubes!
You have 10 minutes to finish the test
Good luck 

23. Homework Do the exercise at your modul from
page
You must collect your homework next
meeting.