Area of Plane Figures – JSS3 Mathematics Lesson Note (Second Term)

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Lesson Notes

Topic: Area Of Plane Figures

The area is the size of a surface.

Triangle

Area = ½ × b × h

b = base

h = vertical height

Rectangle

Area = w × h

w = width

h = height

Trapezoid (US)

Trapezium (UK)

Area = ½(a+b) × h

h = vertical height

Ellipse

Area = πab

Note: h is at right angles to b:

Square

Area = a2

a = length of side

Parallelogram

Area = b × h

b = base

h = vertical height

Circle

Area = π × r2

Circumference = 2 × π × r

r = radius

JSS3 Second Term · 6 topics