## Chapter 20 - Constructions of Quadrilaterals Exercise Ex. 20.1

Question 1 Solution 1        Question 2 Solution 2    Question 3 Solution 3   Question 4 Solution 4 Question 5 Solution 5 Question 6 Solution 6 Question 7 Solution 7  Question 8 Solution 8 Question 9 Solution 9  Question 10 Solution 10 Question 11 Solution 11  Question 12 Solution 12  Question 13 Solution 13 Question 14
Construct a rectangle ABCD, when
AD = 3.2cm and diagonal BD = 5.5cm. Measure CD.
Solution 14
Steps of construction:
1. Draw AD = 3.2 cm
3. With D as centre and radius BD = 5.5 cm, draw an arc to cut AX at point B.
4. Join BD.
5. With B as centre and radius 3.2 cm draw an arc and with D as centre and radius = AB, draw another arc to cut the previous arc at C.
6. Join BC and CD.
Thus, ABCD is the required rectangle.
CD = 4.5 cm Question 15
Construct a rectangle ABCD, when
AB = 5cm and BC = 6.2cm.
Solution 15
Steps of construction:
1. Draw BC = 6.2 cm
2. Through B, draw BP such that ∠B = 90°
3. From BP, cut BA = 5 cm
4. With A and C as centres and radii 6.2 cm and 5 cm respectively, draw arcs cutting each other at D.
Thus, ABCD is the required triangle. Question 16 Solution 16  Question 17 Solution 17  Question 18 Solution 18 Question 19
Construct a rectangle PQRS, when its
Area = 21 cm2 and length = 4.2cm
Solution 19
Since area of rectangle = 21 cm2
And, length = 4.2 cm
Breadth = Area ÷ Length = 21 ÷ 4.2 = 5 cm
Steps of construction:
1. Draw BC = 5 cm
2. Through B, draw BP such that ∠B = 90°
3. From BP, cut BA = 4.2 cm
4. With A and C as centres and radii 5 cm and 4.2 cm respectively, draw arcs cutting each other at D.
Thus, ABCD is the required triangle. Question 20
Construct a rectangle PQRS, when its
Area = 33.8cm2 and breadth = 6.5cm
Solution 20
Since area of rectangle = 33.8 cm2
Length = Area ÷ Breadth = 33.8 ÷ 6.5 = 5.2 cm
Steps of construction:
1. Draw BC = 6.5 cm
2. Through B, draw BP such that ∠B = 90°
3. From BP, cut BA = 5.2 cm
4. With A and C as centres and radii 6.5 cm and 5.2 cm respectively, draw arcs cutting each other at D.
Thus, ABCD is the required triangle. Question 21 Solution 21 Question 22 Solution 22 