NCERT Solutions for Class 8 Maths Chapter 11 Exercise 11.1 in Hindi and English medium updated for CBSE session 2022-2023.

## 8th Maths Exercise 11.1 Solution in Hindi and English Medium

### Class 8 Maths Chapter 11 Exercise 11.1 Solution

Class VIII Mathematics NCERT book Ex. 11.1 of chapter 11 Mensuration updated for academic session 2022-23 free to use or download in PDF file format. Get here all the NCERT solutions in text and videos format free. All the questions of mensuration ex. 11.1 of grade 8 is done step by step using simple formulae. Solutions are made easy to understand and are free to use online or offline.

Class: 8 | Mathematics |

Chapter: 11 | Exercise: 11.1 |

Topic Name: | Mensuration |

Content Type: | PDF Explanation and Video Solution |

Medium: | Hindi and English Medium |

#### Trapezium

A trapezium is a quadrilateral having one pair of parallel opposite sides. suppose, ABCD is a trapezium in which AB || DC Each of the two parallel sides of a trapezium is called its base. Thus, AB and DC are the bases of trap. ABCD. Draw CL êž± AB and DM êž± AB. Let CL = DM = h. Then, h is called the height or altitude of trapezium ABCD. A trapezium ABCD is said to be an isosceles trapezium of its nonparallel sides AD and BC are equal.

##### Area of a Trapezium

Let ABCD be a trapezium in which AB || DC and let h be the height. Then, area of trap. ABCD = {1/2 x (AB + DC) x h} sq. units.

PROOF:

Join AC. Draw CL êž± AB and AM êž± CD (produced ). Let CL = AM = h Area of trap. ABCD = ar (DABC) + ar (DACD)

= {1/2 x AB x CL} + {1/2 x DC x AM}

= {1/2 x AB x h} + {1/2 x DC x h}

= {1/2 x (AB + DC) x h} sq. units.

So, area of a trapezium = Â½ x (sum of parallel sides) x (distance between them).

**Two parallel sides of a trapezium are of lengths 27 cm and 19 cm respectively. and the distance between them is 14 cm. Find the area of the trapezium.**

Area of the trapezium = 1/2 x (sum of parallel sides) x (distance between them)

= {1/2 x (27+19) x 14} cmÂ² = {1/2 x 46 x 14} cmÂ² = (23 x 14) cmÂ² = 322 cmÂ².

**The parallel sides of a trapezium are 25 cm and 13 cm; its nonparallel sides are equal, each being 10 cm. Find the area of the trapezium.**

Let ABCD be the given trapezium in which AB || DC, AB = 25 cm, DC = 13 cm AD = BC = 10 cm.

Draw CL êž± AB and CM || DA, meeting AB at L and M respectively.

Clearly, AMCD is a parallelogram.

So, AM = DC = 13 cm. MB

= (AB â€“ AM) = (25 â€“ 13) cm = 12 cm.

Now, CM = DA = 10 cm and CB = 10 cm.

So, triangle CMB is an isosceles triangle and CL êž± MB

This means, L is the midpoint of MB

So, ML = LB = x MB = Â½ x 12 cm = 6 cm.

Form right triangle CLM, we have:

CL2 = (CM2 â€“ ML2) = {(10)2 â€“ 62} cm = (100 â€“ 36) cm = 64 cm

So, CL = âˆš64 cm = 8 cm

Hence, height of the trapezium = 8 cm.

So, area of trap. ABCD = Â½ x (25 + 13) x 8 cmÂ² = Â½ x 38 x 8 cmÂ²

= (38 x 4) cm = 152 cmÂ²

**Is a trapezium a rhombus?**

No, because a trapezoid has only one pair of parallel sides. … If their two pairs of sides are equal, it becomes a rhombus, and if their angles are equal, it becomes a square.**What is the area and perimeter of trapezium? Find the area of the trapezium, in which the sum of the bases (parallel sides) is 60 cm and its height is 20 cm.**

We know that, Area of a Trapezium, A = h(a+b)/2 square units.

A = 20 (60)/2 = 600 cm2

Perimeter = Sum of all the sides = AB + BC + CD + DA.

Perimeter = 2 x 60 = 120 cm**What is a trapezium in math?**

A trapezoid, also known as a trapezium, is a flat closed shape having 4 straight sides, with one pair of parallel sides.**How find the area of a trapezium?**

The area of a trapezium is computed with the following formula: Area = 1 2 Ã— Sum of parallel sides Ã— Distance between them.

### How many questions are there in exercise 11.1 of class 8 Maths?

There are only five questions in 8th Mathematics exercise 11.1 and all the questions are easy to solve. The examples given just before the exercise are also important for examination.

### Is exercise 11.1 of 8th math easy to solve?

We have to learn and understand formulae and their implementation. If we do so, the exercise 11.1 of class 8 mathematics is very easy otherwise it is difficult to understand.

### Which is the most important questions of exercise 11.1 of class VIII Math?

In class VIII Maths exercise 11.1 only 5 questions are given as exercises. The 5th questions is little bit tricky rest are based on formulae only.