RS Aggarwal Solutions Class 8 Chapter-18 Area of a Trapezium and a Polygon (Ex 18A) Exercise 18.1 - Free PDF

RS Aggarwal Class 8 exercise 18 contains questions of the chapter- Area of a trapezium and a polygon. From an examination point of view, these are some crucial sets of questions that are commonly asked as long answer type questions. Preparing RS Aggarwal Class 8 Chapter 18 Exercise 18A well will allow you to score better in your exams.

Area of Trapezium= ½ (Sum of parallel sides) X ( perpendicular distance between the parallel sides)

Polygons are 2-d shapes made up of straight lines and are closed figures. Some common polygons are triangle, square, rectangle, rhombus etc. RS Aggarwal Math Class 8 ex 18A contains word problems and figure problems on these shapes. You will have to find the area of polygons using the area of different shapes. Other commonly used formulas in the chapter are-

Area of Triangle= ½ * base * perpendicular height

Area of Square=(Side)2

Area of rectangle = l X b

Area of Rhombus = ½  * (diagonal 1) * ( diagonal 2)

Class 8 Math Weightage Marks

The examination pattern of Class 8 is given below. To prepare for their exams, students can download the free PDF RS Aggarwal Class 8 ex 18A solutions. The paper is divided into four sections- Section A, B, C and D. RS Aggarwal Class 8 MathExercise 18A solutions are prepared by our subject experts at Vedantu to give students an in-depth understanding of the chapter. 

• Section A - 12 questions X 1 Marks

• Section B - 12 questions X 2 Marks

• Section C - 8 questions X 3 Marks

• Section D - 5 questions X 4 marks

The chapter-wise weightage is given below. Students can use this information to plan their preparations well. A better understanding of the syllabus contents, it will help you to prepare for the examinations well. To practice questions from different chapters, download the RS Aggarwal Math Class 8 ex 18A PDF here.

Benefits of RS Aggarwal Solutions Class 8 Math Ex 18A

RS Aggarwal Class 8 Math Exercise 18A PDF is designed to give students an in-depth understanding of the concepts of the chapter and the different types of questions asked in the examination. Practicing questions from RS Aggarwal Class 8 exercise 18 will make the students familiar with what type of questions are commonly asked in the examinations. For a precise and logical explanation of these questions download the RS Aggarwal solutions Class 8 Math ex 18A PDF.

It is critical to put consistent efforts into practicing word problems and understanding the figures to answer the questions from this chapter. Benefits of RS Aggarwal Solutions Class 8 ex 18 a are given below:

• The solutions are prepared by our subject experts at Vedantu with years of experience in teaching.

• The answers are written simply and logically to improve concept-based understanding.

• The solutions are prepared as per the CBSE guidelines to help students score well in their exams.

• Practicing solutions from the RS Aggarwal Math Class 8 ex 18A will allow students to format their answers in the exams better.

Questions

1. The parallel sides of a trapezium are in the ratio 3:5 and the distance between them is 12 cm. Find the length of parallel sides if the area of the trapezium =384 cm2.

Ans: The parallel sides of the trapezium are in the ratio of 3:5.Let the sides of the trapezium be 3x and 5x. The sum of parallel sides = 8x

According to the question, area = 384 cm2 and the distance between the two sides =12cm.

Area of Trapezium= ½ (Sum of parallel sides) * ( perpendicular distance between the parallel sides)

Area of Trapezium= ½ * (8x) * 12cm

384=8x * 6

64 = 8x

x = 8

The length of the parallel sides will be

3x = 3*8=24cm

5x = 5*8=40cm

The length of the parallel sides is 24 cm and 40cm.

2. Find the length of the side of a rhombus of area 120 cm2 while the length of a diagonal is given = 24cm.

Ans: Let the side of the rhombus be = a.

Area of Rhombus = ½ * (diagonal 1) * ( diagonal 2)

Area of Rhombus= ½ * 24 * D2

120 * 2=24 * D2

5*2=D2

Length of diagonal = 10cm

The diagonals of the rhombus bisect each other at right angles. Looking at any one of the triangles formed by the two diagonals and the side of the rhombus. We can find the length of the side of the rhombus using the Pythagoras theorem.   

D1/2 = 12 cm

D2/2 = 5cm

(5)2 + (12)2 = a2

25 + 144 = a2

√169 = a

a=13cm

Advantages of Vedantu

Vedantu has always been the best guide in every step of the preparation.

There are plenty of reasons and a few are stated as below.

• The solutions are explained very comprehensively.

• The language is simple and easy to understand by all the students.

• The solutions are systematic according to the chapter.

• They are prepared by experts having excellent subject knowledge.

• The syllabus is according to the CBSE syllabus so there is no chance of any confusion.

General Tips for Math Preparation.

Math is the easiest subject and can be very well ripped with regular practice. Any subjects for that matter it is not possible to learn in a short span. It needs continuous reading and understanding.

This subject cannot be scored by memorizing or just going through before the exam. It needs regular practice of solving the problems with logical thinking.

So practice each topic with full understanding. Take care of the steps while solving the problems.

Learn the formulas well. Write the formulas and read it every day so that all the formulas will be at the fingertips which will be easier while solving the problems.

Take the mock tests regularly so that you will enhance your speed while solving the problems.

Once the syllabus is completed, solve the previous year question paper so that you will get an exact idea of the real exam pattern.

Developing time management skills which is very important. 

Think positive and earn with focus.