Class 9th | Chapter 12 Herons formula | Practices paper - 1

Red Star(*) is a Correct Answer

1. The area of an equilateral triangle with side 4√3 cm is :(√3 = 1.732 )

1. 20 cm2
2. 20√3 cm2
3. 18.784 cm2
4. 20.784 cm2*

2.The area of ∆ABC in which AB = BC = 4 cm and ∠B=90^o is :

1. 16 cm2
2. 8 cm2*
3. 4 cm2
4. 12 cm2

3.The perimeter of an equilateral triangle is 60m. its area is :

1. 10√3 m2
2. 100√3 m2*
3. 15√3 m2
4. 20√3 m2

4.The edge of a triangular board are 6 cm , 8 cm , 10 cm. the cost of painting it at rate of 9 paise per cm2 is :

1. Rs 2
2. Rs 3
3. Rs 2.16*
4. Rs 2.48 

5.The Side of a triangle are 7 cm , 24 cm and 25 cm. its area is :

1. 168 cm2
2. 84 cm2*
3. 87.5 cm2
4. 300 cm2

6.The base of a right triangle is 8cm and hypotenuse is 10cm , its area will be :

1. 24 sq cm *
2. 40 sq cm 
3. 48 sq cm 
4. 80 sq cm 

7.The sides of a triangle are 35 cm , 54 cm and 61 cm, respectively  . the length of its longest altitude

1. 16√5 cm 
2. 10√5 cm 
3. 24√5 cm *
4. 28 cm 

8.Area of an equilateral triangle , of each side 2a units is 

1. √3/4 a^2  sq.unit 
2. √3/2 a^2  sq.unit 
3. √3 a^2  sq.unit *
4. 2√3 a^2  sq.unit 

9.The length of each side of an equilateral triangle having an area of 9√3 cm2 is 

1. 8 cm 
2. 36 cm
3. 4 cm
4. 6 cm *

10.The sides of a triangle are in the ratio of 3 : 4 : 5 if perimeter is 36 cm , then what is its area ?

1. 32 cm2
2. 67 cm2
3. 54 cm2*
4. 72 cm2

11.Area of an isosceles right triangle is 8 cm2 .its hypotenuse 

1. √32 cm*
2. 4 cm
3. 4√3 cm
4. 2√6 cm 

12.If s - a = 90 , s - b =50 , s – c = 10 what value of a ;

1. 50
2. 60*
3. 70
4. 30

1. Find the perimeter of an isosceles right triangle having an area of 100 cm^2
2. Side of a triangle are 70cm, 80 cm and 90 cm . find its area 
3. The area of a triangle is 48 cm^2. Its base 12 cm. find its corresponding altitude 
4. The base of an isosceles triangle is 4 cm and its perimeter is 20cm . find its area 

A food pyramid is a representation of the optimal number of servings to be eaten each day from each of basic food groups. It is designed to make healthy eating easier. Health care NGO in India working for underprivileged children. In rural areas health statistics are continue to poor. In this direction Health statistics are continue to poor. In this direction Health Care India has made the children under the age of 13 aware of “food pyramid” by telling the importance of different food groups such as carbohydrates, fats, vitamins, proteins, minerals etc. The models of food pyramid which they have used triangle with sides 10 cm, 10 cm, 12 cm.

Now answer the following question 

1.  The semiperimeter of a triangle is:

A. 10cm
B. 21cm
C. 20cm*
D. 16cm

2. find the area of food pyramid which is in shape of triangle 

A. 20 sq. cm 
B. 30 sq. cm 
C. 42 sq. cm*
D. 48 sq. cm 

3. find the height of triangle 

A. 8 cm *
B. 10 cm
C. 12 cm
D. 14 cm 

4. which type of triangle is given in food pyramid ?

A. Scalene triangle 
B. Isosceles triangle 
C. Equilateral triangle *
D. Right- angle Triangle 

5. The pyramid was not coloured. It got painted at rate of Rs 19.75 per m2. What will be total cost ?

A. Rs 800
B. Rs 878 
C. Rs 948*
D. Rs 1000