NCERT Solutions for Class 9 Maths Chapter 11: Constructions

Collegedunia Team logo

Collegedunia Team

Content Curator

The NCERT Solutions for Class 9 Maths Constructions are provided in this article. Construction deals with how to accurately draw shapes, angles, and lines. Many geometric figures can be precisely constructed using a variety of construction methods. 

Class 9 Maths Chapter 11 Constructions belong to Unit 4 Geometry which has a weightage of 28 marks in the Class 9 Maths Examination. NCERT Solutions for Class 9 Maths for Chapter 11 cover the following important concepts: 

  1. 2D and 3D Figures
  2. Line Segment
  3. Formula Of Perimeter Shapes

Download: NCERT Solutions for Class 9 Mathematics Chapter 11 pdf


NCERT Solutions for Class 9 Mathematics Chapter 11

NCERT Solutions Mathematics NCERT Solutions Mathematics NCERT Solutions Mathematics NCERT Solutions Mathematics NCERT Solutions Mathematics NCERT Solutions Mathematics NCERT Solutions Mathematics NCERT Solutions Mathematics NCERT Solutions Mathematics NCERT Solutions Mathematics NCERT Solutions Mathematics NCERT Solutions Mathematics NCERT Solutions Mathematics NCERT Solutions Mathematics NCERT Solutions Mathematics NCERT Solutions Mathematics

Important Topics in Class 9 Maths Chapter 11 Constructions

Important Topics in Class 9 Maths Chapter 11 Constructions are elaborated below:

2D and 3D Figures

Geometrically, 2D figures, otherwise known as two-dimensional objects, that can be drawn on a plane surface. 3D-shapes, howerver, are called three-dimensional objects or solids that include three dimensions. 

Example: Determine the surface area of a cube, assuming that its edge length is 40 cm.

Solution: The edge of cube is given as = 40cm
As per formula, the surface area of a cube = 6a2 (a = the edge length)
Hence, the surface area of the cube is = 6 (40) 2 = 9600 sq.cm

Line Segment

Line segments can be defined as points along a line which are found to be bounded by two distinct points. 

Example: What are some properties of a Line Segment?

Solution: The properties of a line segment include:

  • A line has infinite ends which cannot be measured.
  • However, a line segment has a start point and an endpoint which means it can be measured.
  • Line segments normally include a defined length, which lead them to form the sides of any polygon.

Formula of Perimeter Shapes

Perimeter, in geometry, can be defined as the length of a closed figure's boundary. The perimeter formula for regular polygons is usually expressed using algebraic equations. 

Perimeter of Different Geometric Figures:

  • Perimeter of a Hexagon: 6a [where a is the side of a Hexagon]
  • Perimeter of a Parallelogram: 2(b + h) [where b and h are the base and height respectiveley]
  • Perimeter of a Trapezoid: a + b + c + d [where a, b, c and d are the respective lengths of the Trapezoid] 

NCERT Solutions for Class 9 Maths Chapter 11 Exercises:

The detailed solutions for all the NCERT Solutions for Constructions under different exercises are:

Also Read:

Also Check:

Check out:

gh

CBSE X Related Questions

1.

The lengths of 40 leaves of a plant are measured correct to the nearest millimetre, and the data obtained is represented in the following table :

Length (in mm)

Number of leaves

118 - 126

3

127 - 135 

5

136 - 144

9

145 - 153

12

154 - 162

5

163 - 171

4

172 - 180

2

Find the median length of the leaves. 
(Hint : The data needs to be converted to continuous classes for finding the median, since the formula assumes continuous classes. The classes then change to 117.5 - 126.5, 126.5 - 135.5, . . ., 171.5 - 180.5.)

      2.

      A vertical pole of length 6 m casts a shadow 4 m long on the ground and at the same time a tower casts a shadow 28 m long. Find the height of the tower.

          3.

          Form the pair of linear equations for the following problems and find their solution by substitution method.

          (i) The difference between two numbers is 26 and one number is three times the other. Find them.

          (ii) The larger of two supplementary angles exceeds the smaller by 18 degrees. Find them.

          (iii) The coach of a cricket team buys 7 bats and 6 balls for Rs 3800. Later, she buys 3 bats and 5 balls for Rs 1750. Find the cost of each bat and each ball.

          (iv) The taxi charges in a city consist of a fixed charge together with the charge for the distance covered. For a distance of 10 km, the charge paid is Rs 105 and for a journey of 15 km, the charge paid is Rs 155. What are the fixed charges and the charge per km? How much does a person have to pay for travelling a distance of 25 km.

          (v) A fraction becomes\(\frac{ 9}{11}\), if 2 is added to both the numerator and the denominator. If, 3 is added to both the numerator and the denominator it becomes \(\frac{5}{6}\). Find the fraction.

          (vi) Five years hence, the age of Jacob will be three times that of his son. Five years ago, Jacob’s age was seven times that of his son. What are their present ages?

              4.
              Which of the following are APs? If they form an AP, find the common difference d and write three more terms.
              (i) 2, 4, 8, 16, . . . .
              (ii) \(2, \frac{5}{2},3,\frac{7}{2}\), . . . .
              (iii) – 1.2, – 3.2, – 5.2, – 7.2, . . . .
              (iv) – 10, – 6, – 2, 2, . . .
              (v) 3, \(3 + \sqrt{2} , 3 + 3\sqrt{2} , 3 + 3 \sqrt{2}\) . . . .
              (vi) 0.2, 0.22, 0.222, 0.2222, . . . .
              (vii) 0, – 4, – 8, –12, . . . .
              (viii) \(\frac{-1}{2}, \frac{-1}{2}, \frac{-1}{2}, \frac{-1}{2}\), . . . .
              (ix) 1, 3, 9, 27, . . . .
              (x) a, 2a, 3a, 4a, . . . .
              (xi) a, \(a^2, a^3, a^4,\)  . . . .
              (xii) \(\sqrt{2}, \sqrt{8} , \sqrt{18} , \sqrt {32}\) . . . .
              (xiii) \(\sqrt {3}, \sqrt {6}, \sqrt {9} , \sqrt {12}\) . . . . .
              (xiv) \(1^2 , 3^2 , 5^2 , 7^2\), . . . .
              (xv) \(1^2 , 5^2, 7^2, 7^3\), . . . .

                  5.

                  Solve the following pair of linear equations by the substitution method. 
                  (i) x + y = 14 
                      x – y = 4   

                  (ii) s – t = 3 
                      \(\frac{s}{3} + \frac{t}{2}\) =6 

                  (iii) 3x – y = 3 
                        9x – 3y = 9

                  (iv) 0.2x + 0.3y = 1.3 
                       0.4x + 0.5y = 2.3 

                  (v)\(\sqrt2x\) + \(\sqrt3y\)=0
                      \(\sqrt3x\) - \(\sqrt8y\) = 0

                  (vi) \(\frac{3x}{2} - \frac{5y}{3}\) =-2,
                      \(\frac{ x}{3} + \frac{y}{2}\) = \(\frac{ 13}{6}\)

                      6.

                      The following frequency distribution gives the monthly consumption of electricity of 68 consumers of a locality. Find the median, mean and mode of the data and compare them

                      Monthly consumption 
                      (in units)

                       Number of consumers

                      65 - 85 

                      4

                      85 - 105

                      5

                      105 - 125

                      13

                      125 - 145

                      20

                      145 - 165

                      14

                      165 - 185

                      8

                      185 - 205

                      4

                          Comments



                          No Comments To Show