Wednesday 10 August 2011

9th Test Paper : HERON’S FORMULA & SURFACE AREAS AND VOLUMES

Section A 1 mark each
1. Heron was born in ____________ in ___________.
2. Heron formula is used to find area of triangle when _______________.
3. Find the area of a triangle, two sides of which are 8 cm and 11 cm and the perimeter is 32 cm.
Section B 2 marks each

4. The sides of a triangular plot are in the ratio of 3 : 5 : 7 and its perimeter is 900 m. Find its area.

5. An isosceles triangle has perimeter 44 cm and each of the equal sides is 14cm. Find the area of the triangle.

6. The perimeter of a rhombus is 240cm and one of its diagonals is 80cm. Find its area using Heron.s formula. Section C 3 marks each

7. Find area of equilateral triangle of side 4a using Heron.s formula. Using this formula find area of an equilateral triangle whose perimeter is 540cm.

8. The sides of a quadrilateral are 5cm, 12cm, 15cm and 20cm. The angle between first two sides is 90˚ Find the area of quadrilateral.

9. One side of a right triangle is 8 cm and the difference between other two sides is 4 cm. Find its area by Heron.s formula.

Section D 6 marks each


10. A field is in the shape of a trapezium whose parallel sides are 35 m and 15 m. The non-parallel sides are 16 m and 18 m. Find the area of the field.


11 The sides of a triangular field are 600m, 640m and 700m. (a) Find the cost of fencing at the rate of Rs. 50 per metre leaving doors of 2m on each side (b) Find cost of levelling the field at Rs. 50 per square metre .

12 Mary wants to decorate her Christmas tree. She wants to place the tree on a wooden box covered with colored paper with picture of Santa Claus on it. She must know the exact quantity of paper to buy for this purpose. If the box has length, breadth and height as 80 cm, 40 cm and 20 cm respectively how many square sheets of paper of side 40 cm would she require?

13 Savitri had to make a model of a cylindrical kaleidoscope for her science project. She wanted to use chart paper to make the curved surface of the kaleidoscope. What would be the area of chart paper required by her, if she wanted to make a kaleidoscope of length 25 cm with a 3.5 cm radius?

14.A hemispherical dome of a building needs to be painted .If the circumference of the base of the dome is 17.6 m, find the cost of painting it, given the cost of painting is Rs 5 per 100 cm2.

15. A wall of length 10 m was to be built across an open ground. The height of the wall is 4 m and thickness of the wall is 24 cm. If this wall is to be built up with bricks whose dimensions are 24 cm × 12 cm × 8 cm, how many bricks would be required?

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