# Area Calculation - Online Quiz

Following quiz provides Multiple Choice Questions (MCQs) related to **Area Calculation**. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using **Show Answer** button. You can use **Next Quiz** button to check new set of questions in the quiz.

Q 1 - A rectangle measures 8cm on length and its slanting measures 10 cm. what is the border of the rectangle?

### Answer : C

### Explanation

second side = √{(10)^{2}-(8)}^{2}= √(100-64) =√36= 6cm Perimeter = 2(8+6) = 28cm

Q 2 - The region of a rectangle is 12sq. mtr. Also, its length is 3 times that of its expansiveness. What is the edge of the rectangle?

### Answer : D

### Explanation

Let the breadth be x mtr. then its length = 3x ∴ 3x*x= 12 ⇒ x^{2}= 4 ⇒x=2 ∴ L= 6m, b=2m ⇒perimeter = 2(6+2) m = 16m

Q 3 - If the length of the rectangle is expanded by 20% and its expansiveness is diminished by 20%, then its zone:

### Answer : B

### Explanation

Let, length = x mtr. And breadth = y mtr. Then, area =(xy) m^{2}New length = (120/100*x) m = 6x/5 m, new breadth= (80/100*y) m = 4y/5 m New area = (6x/5 *4y/5) m^{2}= (24/25xy) m^{2}Decrease in area = (xy- 24/25xy) m^{2}Decrease % = (xy/25*1/xy*100) %= 4%

Q 4 - The covering of a room twice the length it is board at the rate of 50 p for every square mtr. costs rs. 12.25 And the expense of painting its dividers the rate of 9 p for every square mtr. is rs. 6.30. The tallness of the room is:

### Answer : A

### Explanation

Let breadth = x mtr. Then, length = 2x mtr. Area of the floor = 1225/50 m^{2}= 49/2 m^{2}∴ X*2x= 49/2 ⇒x^{2}=49/4 ⇒x=7/2 ∴ L = 7m, b= 7/2 m Area of 4 walls = 630/9 m^{2}= 70 m^{2}2(7+ 7/2)* h= 70 ⇒ 2*21/2*h =70 ⇒h =70/21 m = 10/3m

Q 5 - The length of a rectangle is twice than its broadness. On the off chance that the length of this rectangle is expanded by 5cm and broadness is diminished by 5cm, the territory of a rectangle is expanded by 75m^{2}. The length of the rectangle is:

### Answer : C

### Explanation

Let breadth be x cm. Then, length =2x cm (2x-5) (x+5)-x*2x =75 ⇒5x= 100 ⇒x= 20 ∴Length = (2*20) cm =40 cm

Q 6 - The area of an equilateral triangle is 4√3cm^{2}. Each of its side measures.

### Answer : D

### Explanation

Let each side be a cm. then, √3/4 a^{2}= 4√3 ⇒a^{2}=16 ⇒a= 4cm

Q 7 - The sides of a triangular board are 13m, 14m and 15m. The cost of Painting it at rs. 8.75 per m^{2} are:

### Answer : B

### Explanation

s= 1/2 (13+14+15) =21, (s-a)= 8 , (s-b)= 7 and (s-c) 6 Area to be painted = √21*8*7*6 m^{2}=84 m^{2}Cost of painting = rs. (84* 8.75)= rs. 735

Q 8 - A typist uses a paper 30cm*15 cm. He leaves an edge of 2.5cm at the top and the base and 1.25 cm on either side. What rate of paper range around accessible for writing?

### Answer : D

### Explanation

Total area = (30*15) cm^{2}Area used = [(30-1.25*2)* (15-2.5*2)] = (27.5*10) cm^{2}= 275cm^{2}Percentage of area used = (275/450*100) % = 61.1%

Q 9 - The region of a rhombus is 2016cm^{2} and its side is 65cm. The lengths of its diagonals are:

### Answer : B

### Explanation

1/2 d₁* d₂=2016 ⇒d₁*d₂=4032 (1/2 d₁)^{2}+ (1/2 d₂)^{2}= (65)^{2}⇒d₁^{2}+d₂^{2}= 16900 ∴d₁^{2}+d₂^{2}+2d₁d₂ = (16900+8064) =24964 ⇒ (d₁+d₂)^{2}= (158)^{2}⇒d₁+d₂ =158 d₁^{2}+d₂^{2}-2d₁d₂ = (16900-8064) =8836 ⇒ (d₁-d₂)^{2}= (94)^{2}⇒d₁-d₂=94 d₁+d₂=158, d₁-d₂ =94 ⇒2d₁=252 ⇒d₁=126cm ⇒d₂= (158-126) =32 cm ∴diagonals are 126 cm, 32 cm.

Q 10 - What is the region of the shaded bit if every side of the square measures 21cm?

### Answer : C

### Explanation

Area of the shaded region= [(21)^{2}-22/7* (21/2)^{2}] = (441- 693/2) cm^{2}= (441- 346.5) cm^{2}= 94.5 cm^{2}