Area and Perimeter
- The diagonals of a squares is 4√2 cm. The diagonal of another square whose area is double that of the first square is
-
View Hint View Answer Discuss in Forum
Diagonal of square = √2a [a = side]
4√2 = √2 a
a = 4 cm
Now, area of square = a2 = (42) = 16
Side of a square whose area is 2 x 16.
a12 = 32
⇒ a1 = √32 ⇒a14√2Correct Option: A
Diagonal of square = √2a [a = side]
4√2 = √2 a
a = 4 cm
Now, area of square = a2 = (42) = 16
Side of a square whose area is 2 x 16.
a12 = 32
⇒ a1 = √32 ⇒a14√2
Now, diagonal of new square = √2a
= √2x 4 √2
= 8 cm
- The diagonals of two squares are in the ratio of 3 : 2. Find the ratio of their areas.
-
View Hint View Answer Discuss in Forum
Let the diagonals of the squares be 3x and 2x.
∴ Ratio of their areas = [(1/2) (3x2)] / [(1/2) (2x2)]Correct Option: A
Let the diagonals of the squares be 3x and 2x.
∴ Ratio of their areas = [(1/2) (3x2)] / [(1/2) (2x2)] = 9/4
- If the sides of a squares is increased by 25%, then the area of the squares will be increased by
-
View Hint View Answer Discuss in Forum
Required increment = 2a + [a2 / 100] %
Correct Option: C
Required increment = 2a + [a2 / 100] %
= 2 x 25 + [(252)/100)] %
= 50 + (625/100)%
= 56.25%
- The perimeter of two square is 12 cm and 24 cm. The area of the bigger square is how many times that of the smaller?
-
View Hint View Answer Discuss in Forum
Ratio of area of 2 squares = (ratio of perimeter of 2 squares)2
Correct Option: C
Ratio of area of 2 squares = (ratio of perimeter of 2 squares)2
= (24/12)2
= 4
- A cost of cultivating a square field at a rate of ₹ 135 per hectare is ₹ 1215. The cost of putting a fence around it at the rate of 75 paise per meter wouldbe
-
View Hint View Answer Discuss in Forum
Area of the field =1215/135 = 9 hec
= 90000 m2 [1 hec =10000 m2]
∴ Side of the field = √90000 = 300 mCorrect Option: C
Area of the field =1215/135 = 9 hec
= 90000 m2 [1 hec =10000 m2]
∴ Side of the field = √90000 = 300 m
Perimeter of the field = 4 x 300 = 1200 m
Now, cost of putting a fence around field = (1200 x 75)/100 = ₹ 900