Back to: BASIC TECHNOLOGY JSS2
Welcome to Class !!
We are eager to have you join us !!
In today’s Basic Technology class, We will be discussing Area of Plane Figures. We hope you enjoy the class!
Definition of Area:
The area (A) of a closed plane figure is the region of the plane enclosed by the figure’s boundary. The area is measured in square units of length such as square centimetre (cm22) and square metre (m22).
Triangle Area = ½ × b × h b = base h = vertical height 

Square Area = a^{2} a = length of side 

Rectangle Area = w × h w = width h = height 
Parallelogram Area = b × h b = base h = vertical height 

Trapezoid Area = ½(a+b) × h h = vertical height 
Circle Area = π × r^{2} Circumference = 2 × π × r r = radius 

Sector Area = ½ × r^{2} × θ r = radius θ = angle in radians 
Example: What is the area of this rectangle?
The formula is:
Area = w × h
w = width
h = height
We know w = 5 and h = 3, so:
Area = 5 × 3 = 15
Example:
What is the area of a circle where
Radius = r = 3
Area  = π × r^{2}  
= π × 3^{2}  
= π × (3 × 3)  
= 3.14159… × 9  
= 28.27 (to 2 decimal places) 
Example:
What is the area of a triangle where
Height = h = 12
Base = b = 20
Area = ½ × b × h = ½ × 20 × 12 = 120
We have come to the end of this class. We do hope you enjoyed the class?
Should you have any further question, feel free to ask in the comment section below and trust us to respond as soon as possible.
In our next class, we will be talking about Woodwork Machines. We are very much eager to meet you there.
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