31.

The area of the parallelogram whose length is 30 cm, width is 20 cm and one diagonal is 40 cm is

• 
• 
• 
• 

On increasing each side of a square by 50%, the ratio of the area of new square formed and the given square will be

• 9 : 5

• 9 : 3.5

• 9 : 7

• 9 : 7

The area of circle is  square cm. The length of its longest chord (in cm) is

• 36

• 28

• 38

• 38

The area of a rhombus is 256 square cm and one of its diagonals is twice the other in length. Then length of its largest diagonal is

• 32 cm

• 16 cm

• 48 cm

• 48 cm

If the side of a square is  and its diagonal is  then the length of the side of the square would be

• 
• 

• 1 unit

• 1 unit

For an equilateral triangle, the ratio of the in-radius and the ex-radius is

• 1 : 2

• 

• 1 : 3

• 1 : 3

The circumference of a triangle is 24 cm and the circumference of its in-circle is 44 cm. Then the area of the triangle is (taking )

• 56 square cm.

• 84 square cm.

• 48 square cm

• 48 square cm

If a and b are the lengths of the sides of a right triangle whose hypotenuse is 10 and whose area is 20, then the value of (a + b)² is

• 140

• 180

• 120

• 120

If the length of each of two equal sides of an isosceles triangle is 10 cm and the adjacent angle is 45°, then the area of the triangle is

One of the angles of a right-angled is 15°, and the hypotenuse is 1 metre. The area of the triangle (in square cm) is

• 1220

• 1200

• 1250

• 1250