Page 24 - prim 4 كامل

Delta Modern Language Schools
Maths Department
Prim 4 2023-2024

Unit (4) : Area and perimeter

Calculating perimeter:

Perimeter is the distance around the figure

EX: Perimeter of triangle = 5 + 5 + 6 =16 cm

Square Rectangle

All side lengths of square are equal each two opposite side are equal

( S: side length ) (L : Length , w : width)

Perimeter of square = S + S + S + S Perimeter of rectangle = L + W + L + W
=SX4
= 2L + 2W
EX: Find the perimeter of square its side
length 7 cm =(L+W)X2

The perimeter = 7 x 4 = 28 cm EX: Find the perimeter of rectangle
whose dimensions 7 cm ,3 cm
Perimeter of rectangle = ( l+ w ) x 2

= (7+ 3) x 2 = 10 x2 = 20 cm

Side length (s) of square Half of perimeter = length + width

= perimeter of square ÷ 4

Area of square = Side length x itself Area of rectangle = length x width

=SxS =LXW

EX: Find the area of square whose side EX: Find the area of rectangle whose
length 5 cm and width 3 cm
length 5 cm Area of rectangle = L x W = 5 x 3 = 15 2
Area of square = S X S = 5 X 5 = 25 2

EX: Find the side length of a square Width of rectangle = Area ÷ length
whose area is 81 2 Length of rectangle = Area ÷ width

Side length of a square is 9 cm (9 x 9 = 81)

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