PQRS is a quadrilateral in which PQ =4 cms, QR = 9.2 cms, RS = 8cm SP = 6cm ∠ PSR = ∠ PQR = 90° . Find its area.

15 A closed metallic cylindrical box is 1.25m high and it has a base whose radius is 35cm. If the sheet of metal costs Rs. 80 per m². Find the cost of the material used in the box. Find the capacity of box in litres. 16 A rectangular piece of paper of dimensions 22cm by 12cm. is rolled along its length to form a cylinder. Find the volume of the cylinder so formed. 18 Find the surface area of a chalk box whose length, breadth and height are 16cm, 8cm and 6cm respectively. 19 The dimensions of a cuboid are in the ratio of 1:2:3 and its total surface area is 88m². Find its dimensions.