On decreasing each side of an equilateral triangle by 2cm, there is a decrease of  in its area. The length of each side of the triangle is

• 3 cm

• 5 cm

• 6 cm

• 6 cm

12.

The least number of squares tiles of side 41 cm required to pave the ceiling of a room of size 15 m 17cm long and 9m and 2cm broad is

• 902

• 656

• 738

• 738

The length of a rectangle is increased by 25%. To maintain the same area, the breadth has to be increased by

• 20%

• 25%

• 30%

• 30%

The area of the largest triangle that can be inscribed in a semicircle of radius 6m is:

• 36 m²

• 72 m²

• 18 m²

• 18 m²

The area of a rectangle is 60 cm² and its perimeter is 34 cm, then the length of the diagonal is

• 17 cm

• 11 cm

• 15 cm

• 15 cm

The height of an equilateral triangle is 18 cm. Its area is

• .
• 

• 108 square cm.

• 108 square cm.

The sides of a triangle are in the ratio 1/2 : 1/3 : 1/4 and its perimeter is 104 cm. The length of the longest side (in cm) is

• 52

• 48

• 32

• 32

The length and breadth of a rectangular piece of a land are in a ratio 5:3. The owner spent Rs. 6000 for surrounding it from all sides at Rs.7.50 per metre. The difference between its length and breadth is

• 50 metre

• 100 metre

• 150 metre

• 150 metre

The ratio between the area of a square and that of a circle, when the length of a side of the square is equal to that of the diameter of the circle, is (Take π=22/7)

• 14 : 11

• 28 : 11

• 7 : 22

• 7 : 22

A piece of wire 132 cm long is bent successively in the shape of an equilateral triangle, a square and a circle. Then area will be longest in shape of

• Circle

• Equilateral triangle

• Square

• Square