Cube

kali ini aku mau posting hasil presentasi mat-ku; Kubus. tapi ini presentasinya full english. kayaknya perlu juga kalo dishare disini XD happy reads~


CUBE

Definition

A cube is a three-dimensional solid object  that bounded by six square faces with three meeting at each vertex. 

The Properties of Cube

a.  All sides of the cube are shaped square. If you notice, the ABCD, EFGH, ABFE, DCGH, ADHE, and BCGF have a square shape and have the same area.

b. All the size of the edges of cube have same length. Cube edges AB, BC, CD, AD, AE, BF, CG, DH, EF, FG, GH, and EH has same length.

c. Each cube has face diagonal of the same size length.

d. Each cube has same length of space diagonal of the cube.

e. Each plane diagonal of the cube form rectangular shape.

Elements of Cube

a. Vertex

Vertex of the cube is a meeting point or three edges cut point (the point of the cube corner).

In the cube there are eight pieces ABCD.EFGH vertex is:
A, B, C, D, E, F, G, and H.

b. Edges

Cube edges are secant between the sides of the cube. Naming the edges using the notation of two capital letters.
In the cube there are 12 edges ABCD.EFGH the same length, namely :
Base edges : AB, BC, CD, AD
Vertical edges : AE, BF, CG, DH
Top edges : EF, FG, GH, EH

c. Sides of Cube

There are 6 pieces congruent sides of a cube, the position is:

1. the base

2. the front side

3. the upper side

4. back side

5. the left side

6. the right side

d. Face Diagonal

Face diagonal is a segment connecting two points on opposite corners of a cube side.
Diagonal length of the side AC = BD = EG = HF = AF = BE = CH = DG = AH = ED = BG = CF

the formula of the length of face diagonal

e. Space Diagonal

Space diagonal of a cube is a segment connecting two points in the opposite corner of the cube. Cube space diagonals intersect in the middle of the cube.

Diagonal length of the space AG = BH = CE = DF
There are 4 diagonal spaces on a cube with the same length.

the formula of space diagonal

f. Plane Diagonal

Plane diagonal is a area that includes two edges in a cube face. Plane diagonal of a rectangular cube.

There are six areas of the diagonal. Plane diagonal ACGE = BDHF = ABGH = CDEF = ADGF = BCHE

The Cube Nets 

Surface Area of Cube 

 

ABCD.EFGH cube with side length s units

Area of BCGF   = s x s
  = s 2

Surface Area of ​​Cube ABCD.EFGH   = 6 x Area of ​​BCGF
  = 6 x s 2
 
Surface Area cube with side length s units are 6 x s 2 unit area

Volume of Cube 

 

Cube ABCD with side length s units

Base area ABCD   = side x side
  = s x s
  = s 2

 
The cube volume   = area x height of base ABCD
  = s 2 x s
  = s 3

The unit of volume of the cube with side length s is s 3

Example 

1. In addition to take a look at an image of a cube. determine which one is the sides, edges, vertex, plane diagonal, space diagonal, and the face diagonal!

2. From the picture below, find :

  a. the length of the edge BC

  b. The length of face diagonal AC

  c. the length of the space diagonal AF

3. Dhanty wanted to make the box widgets cubes of paper cardboard. If this box edge 12 cm in length, find the area of the cardboard that needed !

4. A surface area of a cube is 54 cm2, if the net build a cube, the length of the edges are...

5. Look at picture below! A cube without a cover which has edges of 5 cm. Find the surface area!

done! -.- hhh~ I've already tired. yah, semoga bermanfaat yaw ^o^ maaf kalo gak rapi *bow*