1. A park, in the shape of a quadrilateral ABCD, has – C = 90°, AB = 9 m, BC = 12 m, CD = 5 m and AD = 8 m. How much area does it occupy? Solution: Let us join B and D, such that ΔBCD is a right-angled triangle. We have area of ΔBCD = (1/2)x base x altitude =(1/2)x 12 x 5 m2 = 30 m2 Now, to find the area of ΔABD, we need the length of BD 2. Find the area of a quadrilateral ABCD in which AB = 3 cm, BC = 4 cm, CD = 4 cm, DA = 5 cm and AC = 5 cm. 3. Radha made a picture of an aeroplane with coloured paper as shown in Fig. Find the total area of the paper used. 4. A triangle and a parallelogram have the same base and the same area. If the sides of the triangle are 26 cm, 28 cm and 30 cm, and the parallelogram stands on the base 28 cm, find the height of the parallelogram. 5. A rhombus shaped field has green grass for 18 cows to graze. If each side of the rhombus is 30 m and its longer diagonal is 48 m, how much area of grass field will each cow be getting? Here, each side of the rhombus = 30 m One of the diagonal = 48 m Since a diagonal divides the rhombus into two congruent triangles. 6. An umbrella is made by stitching 10 triangular pieces of cloth of two different colours (see figure), each piece measuring 20 cm, 50 cm and 50 cm. How much cloth of each colour is required for the umbrella ? Sides of each triangular piece are 7. A kite in the shape of a square with a diagonal 32 cm and an isosceles triangle of base 8 cm and sides 6 cm each is to be made of three different shades as shown in the figure. How much paper of each shade has been used in it? Area of triangle I 8. A floral design on a floor is made up of 16 tiles which are triangular, the sides of the triangle being 9 cm, 28 cm and 35 cm (see figure). Find the cost of polishing the tiles at the rate of 50p per cm2. There are 16 equal triangular tiles. Area of a triangle Sides of the triangle are a = 9 cm, b = 28 cm, c = 35 cm 9. A field is in the shape of a trapezium whose parallel sides are 25 m and 10 m. The non-parallel sides are 14 m and 13 m. Find the area of the field. The given field is in the form of a trapezium ABCD such that parallel sides AB = 10 m and DC = 25 m