Ex 4.5, 4 A parallelogram OKAY where OK = 5.5 cm and KA = 4.2 cm. Is it unique?
In parallelogram,
Opposite sides are equal
∴ YA = OK = 5.5 cm
& YO = KA = 4.2 cm
So, we have 4 sides,
But we require 5 measurements to make a quadrilateral
Since we can have any angle as ∠ O, there can be more than 1 parallelogram with the same sides
So, parallelogram is not unique
In parallelogram,
Opposite sides are equal
∴ YA = OK = 5.5 cm
& YO = KA = 4.2 cm
So, we have 4 sides,
But we require 5 measurements to make a quadrilateral
Since we can have any angle as ∠ O, there can be more than 1 parallelogram with the same sides
So, parallelogram is not unique
Steps of construction
1. Draw side OK of length 5.5 cm
2. Now, we draw 90° from point O
Check Ex 11.1, 1 of Chapter 11 Class 9 NCERT to see how to draw 90°
3. Now, we draw 90° from point K
Taking 4.2 cm as radius, and O as center.
Draw an arc. Mark the point where arc and line intersect as Y
Taking 4.2 cm as radius, and K as center.
Draw an arc. Mark the point where arc and line intersect as A
5. Join YA
Label the sides
∴ OKAY is one of the possible parallelograms

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Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths and Science at Teachoo.