MICRO LESSON 1
2D vs 3D
Picture it:
A square is flat; a cube has length, breadth and height.
Simple:
3D solids occupy space.
Example:
Box, cylinder, cone, sphere.
Quick Check:
Which is 3D: circle or sphere?
MICRO LESSON 2
Cuboid
Picture it:
A cuboid has rectangular faces.
Simple:
TSA=2(lb+bh+hl), volume=lbh.
Example:
Room or carton.
Quick Check:
What is volume of 2×3×4?
MICRO LESSON 3
Cube
Picture it:
All edges are equal.
Simple:
TSA=6a², volume=a³.
Example:
Dice.
Quick Check:
Why 6a²?
MICRO LESSON 4
Cylinder
Picture it:
A cylinder has two circular bases and curved surface.
Simple:
CSA=2πrh, TSA=2πr(r+h), volume=πr²h.
Example:
Water pipe or can.
Quick Check:
What is base area?
MICRO LESSON 5
Cone
Picture it:
A cone has circular base and one vertex.
Simple:
CSA=πrl, TSA=πr(l+r), volume=1/3πr²h.
Example:
Ice-cream cone.
Quick Check:
What is slant height?
MICRO LESSON 6
Sphere
Picture it:
Every surface point is equally distant from centre.
Simple:
Surface area=4πr², volume=4/3πr³.
Example:
Ball.
Quick Check:
How many flat faces?
MICRO LESSON 7
Hemisphere
Picture it:
A hemisphere is half a sphere.
Simple:
CSA=2πr², TSA=3πr², volume=2/3πr³.
Example:
Bowl.
Quick Check:
Why TSA exceeds CSA?
MICRO LESSON 8
Unit Conversion
Picture it:
Volume units are cubed.
Simple:
1 m³=1,000,000 cm³.
Example:
Tank capacity.
Quick Check:
How many cm in 1 m?