cubes

3. In geometry, a cube is a three-
dimensional
Solid object
It has six square faces, or sides,
with three meeting at each vertex.
 All vertices are 90 degrees.
.

4. SHAPE OF A CUBE

5.  Let the length of one side of cube be ‘a’
a
a
a

6. It is easy to see that the cube has
six sides and each side is a square.

7. The area of one square is a × a = a2
Since there are 4 lateral faces, the
lateral surface area, call it LSA is:
LSA = a2 + a2 + a2 + a2
LSA = 4 × a2
Therefore, the LSA of cube is 4a2

8. The area of one square is a × a = a2
 Since there are six faces, the total
surface area, call TSA
TSA is:
SA or TSA = a2 + a2 + a2 + a2 + a2 + a2
TSA = 6 × a2
Therefore, the SA of cube is 6a2

9. Q1) Find the LSA and TSA of a cube if the
length of one
side is 3 cm
Side=3 cm
LSA = 4 × a2
LSA = 4 × 32
LSA = 4 × 9 = 36 cm2
TSA or Surface area = 6 × a2
Surface area = 6 × 32
Surface area = 6 × 3 × 3
Surface area = 54 cm2

10. Q2) Find the surfacearea ofa
cube if the length of one side
is 5 cm.
Q3) Find the LSA and surface
area if the length of oneside
is 6cm.