NCERT Solutions for Class 9 Maths Exercise 11.2 Constructions

In the earlier classes, various types of constructions were already done i.e. construction of triangles with the properties SAS, SSS, ASA and RHS. After this exercise is done, we shall learn some special construction which have been noticed and given in summarized form as below.

Construction 4 – To construct a triangle when we’re give the following measurement, Base, Base angle and Sum of the other two sides. In this construction we shall draw a specific triangle with the given measurements.

There are two methods by which such a triangle can be drawn. You can use any method with which you are comfortable. Construction 5 – To construct a triangle when we’re give the following measurement: Base, Base angle and Difference of the other two sides.

Again, this construction is not difficult. It just requires four steps, but there can be two situations depending on the fact that which of the two given sides is greater.

Construction 6 – How to draw a triangle when the perimeter of the triangle is given and measurement of two base angle is also given. This is a really interesting question and its proof is also interesting.

From an examination point of view any of the construction can be asked. Students are again advised to learn the steps of construction by drawing the diagrams labelling them properly and given the proof too.

Exercise 11.2 – contains just five questions and these are based exactly on the theorems/ construction mentioned above.

By actually constructing the diagrams you will find that chapter 11 from NCERT Solution for Maths class 9 was one of the interesting chapter of geometry. Last but not least, students are advised to repeat the construction regularly before the examination and in particular exercise 11.2.