1. The sides of a triangular plot are in the ratio of 3:5:7 and its perimeter is 300m. Find its area. (3 Marks)
2. Find the area of a quadrilateral ABCD in which AB = 3cm, BC = 4cm, CD = 4cm, DA = 5cm and AC = 5cm. (4 Marks)
3. In Fig., An umbrella is made by stitching 10 triangular pieces of cloth of two different colours, each piece measuring 20cm, 50cm and 50cm. How much cloth of each colour is required for the umbrella? (5 Marks)
4. A field in the shape of a trapezium whose parallel sides are 25m and 10m. The non parallel sides are 14m and 13m. Find the area of the field. (5 Marks)
5. Radha made a picture of an aeroplane with coloured paper as shown in Fig. Find the total are of the paper used. (8 Marks)
Similar Triangles | Introduction Similar figures: Geometric figures which have the same shape but different sizes are known as similar figures. Illustrations: 1. Any two line-segments are similar 2. Any two squares are similar 3. Any two circles are similar Two congruent figures are always similar but two similar figures need not be…
A senior IIT professor has pointed out ‘‘serious blunders’’ in this year’s IIT-JEE test that concluded on Sunday. He claims a clever student can get 93 marks without any preparation. The claim was made by Rajeev Kumar, professor of computer science, IIT Kharagpur. IIT-Madras, which conducted the JEE has, however,…
Similar Triangles | Areas of Similar Triangles Theorem: The ratio of the areas of two similar triangles is equal to the ratio of the squares of their corresponding sides. Given: DABC and DPQR such that DABC ~ DPQR. To prove: $latex \displaystyle \frac{\text{ar}\,(\Delta ABC)}{\text{ar}\,(\Delta PQR)}=\frac{A{{B}^{2}}}{P{{Q}^{2}}}=\frac{B{{C}^{2}}}{Q{{R}^{2}}}=\frac{C{{A}^{2}}}{R{{P}^{2}}}$ Construction: Draw AD ^ BC…
