Page 49 - Math E. Booklet prim 4 (first term 2025)_Neat

Unknown Dimensions

Rectangle

For example,
(1)The area of a rectangle is 32 cm2, and its length is 8 cm.

Find its width and its perimeter.
Answer
Width = Area ÷ length = 32 ÷ 8 = 4 cm.
Perimeter = (L + W ) × 2 = (4 + 8) × 2 = 24 cm.

(2)The perimeter of a rectangle is 20 cm, and its width 3 cm.
Find its length and its area.

Answer
Length = Half perimeter - width = 10 – 3 = 7 cm
Area = L × W = 7 × 3 = 21 cm2

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