Exercise 3.4
Question 1
State whether True or False:
(a) All rectangles are squares.
(b) All rhombuses are parallelograms.
(c) All squares are rhombuses and also rectangles
(d) All squares are not parallelograms.
(e) All kites are rhombuses.
(f) All rhombuses are kites.
(g) All parallelograms are trapeziums.
(h) All squares are trapezium.
Answer:
(b), (c), (f), (g), (h) are true; others are false.
Solution:
(a) False (b) True (c) True (d) False (e) False
(f) True (g) True (h) True
Question 2
Identify all the quadrilaterals that have:
(a) Four sides of equal length (b) Four right angles
Answer:
(a) Rhombus; Square (b) Squares : Rectangle
Solution:
(a) Rhombus; Square
(b) Squares : Rectangle
Question 3
Explain how a square is
(i) A quadrilateral (ii) A parallelogram (iii) A rhombus (iv) A rectangle
Answer:
(i) A square has four sides, so it is a quadrilateral.
(ii) A square is a rectangle (with adjacent sides equal).
A rectangle is a parallelogram (with an angle a right angle).
Hence, a square is a parallelogram.
(iii) A square is a rectangle with adjacent sides equal.
A rectangle is a parallelogram (with an angle a right angle).
Therefore, a square is a parallelogram with adjacent sides equal.
In a parallelogram, opposite sides are equal.