119
Rectangles and squares
Textbook Part 4, pp. 18–19
GoalKnow the properties of rectangles and squares and find their perimeters.
New words
rectangle · to‘g‘ri to‘rtburchakopposite sides · qarama-qarshi tomonlarlength / width · uzunlik / eni
Explanation
A rectangle has equal opposite sides and all right angles. A square is a rectangle with all sides equal. A rectangle’s perimeter: length + width + length + width.
Worked examples
A rug 5 dm by 3 dm: P = 5 + 3 + 5 + 3 = 16 dm.
A square rug’s side equals the rectangle rug’s short side (3 dm): P = 3 + 3 + 3 + 3 = 12 dm.
Class activity
Children find rectangular things in the room (book, window, board), measure opposite sides and check that they are equal.
Practice
1
A rectangle is 8 cm by 2 cm. P = ?
20 cm
2
A square has 10 cm sides. P = ?
40 cm
3
Is a square a rectangle?
Yes — a rectangle with all sides equal
4
One side of a rectangle is 6 cm. The opposite side?
6 cm