THE BRITISH CO-ED HIGH SCHOOL
SUBJECT – MATHEMATICS
TOPIC – AREA AND PERIMETER
WORKSHEET – 1
1. Find the area of a triangle whose sides are 18 cm, 24 cm and 30 cm. Also, find the length of
altitude corresponding to the largest side of the triangle.
2. The sides of a triangular field are in the ratio 5 : 3 : 4 and its perimeter is 180 m. Find:
(i) its area.
(ii) altitude of the triangle corresponding to its largest side.
(iii) the cost of levelling the field at the rate of ₹ 10 per square metre.
3. Find the area of an isosceles triangle with perimeter is 36 cm and base is 16 cm.
4. The base of an isosceles triangle is 24 cm and its area is 192 sq. cm. Find its perimeter.
5. Each of equal sides of an isosceles triangle is 4 cm greater than its height. If the base of the triangle
is 24 cm; calculate the perimeter and the area of the triangle.
6. The area of an equilateral triangle is 36√𝟑sq. cm. Find its perimeter.
7. Calculate the area and the height of an equilateral triangle whose perimeter is 60 cm.
8. The given figure shows a right-angled triangle ABC and an equilateral triangle BCD. Find the area
of the shaded portion.
9. Find the area of a quadrilateral one of whose diagonals is 30 cm long and the perpendiculars from
the other two vertices are 19 cm and 11 cm respectively.
10. The diagonals of a quadrilateral are 16 cm and 13 cm. If they intersect each other at right angles;
find the area of the quadrilateral.
11. A rectangular plot 85 m long and 60 m broad is to be covered with grass leaving 5m all around.
Find the area to be laid with grass.
12. How many tiles, each of area 400 cm2, will be needed to pave a footpath which is 2 m wide and
surrounds a grass plot 25 m long and 13 m wide?
13. The shaded region of the given diagram represents the lawn in the form of a house. On
the three sides of the lawn there are flowerbeds having a uniform width of 2 m.
(i) Find the length and the breadth of the lawn.
(ii) Hence, or otherwise, find the area of the flower-beds.
14. Two adjacent sides of parallelogram are 24 cm and 18 cm. If the distance between the
longer sides is 12 cm; find the distance between the shorter sides.
15. Two adjacent sides of parallelogram are 28 cm and 26 cm. If one diagonal of it is 30 cm
long; find the area of the parallelogram. Also, find the distance between its shorter sides.
