RBSE Solutions for Class 9 Maths Chapter 11 Area of Plane Figures Ex 11.1 is part of RBSE Solutions for Class 9 Maths. Here we have given Rajasthan Board RBSE Class 9 Maths Solutions Chapter 11 Area of Plane Figures Exercise 11.1.

Board |
RBSE |

Textbook |
SIERT, Rajasthan |

Class |
Class 9 |

Subject |
Maths |

Chapter |
Chapter 11 |

Chapter Name |
Area of Plane Figures |

Exercise |
Ex 11.1 |

Number of Questions Solved |
7 |

Category |
RBSE Solutions |

## Rajasthan Board RBSE Class 9 Maths Solutions Chapter 11 Area of Plane Figures Ex 11.1

Question 1.

The base and height of a triangle are 20 cm and 6 cm. Find the (RBSESolutions.com) area of the triangle.

Solution.

Area of triangle = \(\frac { 1 }{ 2 }\) × base × altitude

= \(\frac { 1 }{ 2 }\) × 20 × 6 = 60 cm²

Question 2.

Find the area of the triangle whose sides are 15 cm, 25 cm and 30 cm respectively.

Solution.

Let a = 15 cm, b = 25 cm and c = 30 cm

Question 3.

Find the area of an isosceles triangle, the measure (RBSESolutions.com) of one of its equal sides being 8 cm and the third side is 4 cm.

Solution.

Area of an isosceles triangle

Question 4.

Find the area of an equilateral (RBSESolutions.com) triangle whose side is 20 cm.

Solution.

Area of an equilateral triangle

= 100√3 sq. cm.

Question 5.

A triangular plot whose two sides are 8 cm and 15 cm and its perimeter is 40 cm, then find the area of the triangular plot.

Solution.

Perimeter of triangular plot = sum of all the three sides

40 = 8 + 15 + third side

=> Third side = 40 – 23 = 17 cm

Area of triangular plot

Question 6.

A triangular table whose sides are in the ratio 3:4:5 and (RBSESolutions.com) its perimeter is 36 m, then find the area of triangular table.

Solution.

Sides of table are given as 3 : 4 : 5

i.e. sides are 3x, 4x and 5x

∴Perimeter = 36 m

i.e. 3x + 4x + 5x = 36

⇒ 12x = 36

⇒ x = 3

∴Sides are 3x = 3 x 3 = 9 m

4x = 4 x 3 = 12 m

5x = 5 x 3 = 15 m

Area of triangular table

Question 7.

The sides of a triangular field are 20 m, 51 m and 37 m. Find the (RBSESolutions.com) number of flowerbeds that can be prepared if each bed is to contain 2 x 3 sq. metre space.

Solution.

Let sides of a triangular field be

a = 20 m, 6 = 51 m and c = 37 m

We hope the given RBSE Solutions for Class 9 Maths Chapter 11 Area of Plane Figures Ex 11.1 will help you. If you have any query regarding Rajasthan Board RBSE Class 9 Maths Solutions Chapter 11 Area of Plane Figures Exercise 11.1, drop a comment below and we will get back to you at the earliest.

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