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Po i ——, , ( 700, , “so |] = 2004 by (ransposing 2 on LHS), 350 = (200 + b), , . 350-200 = b (Transposing 200 on LHS), , > 150m = b, , therefore, the breadth of the rectangular field is 150 m, , Using the conversion rate, 1m = 10. dm, we get, 150m = 150 » 10dm = 1,500 dm, aus So, the breadth of the rectangular field Is 1,500 dm., , geumpte 8 Arnab jogs around a rectangular park of length 60 m and breadth 40 m. If he takes 10 rounds of the, park every day, how much distance does he cover ina day, in km?, , on We have, length of the park = 60m, Breadth of the park = 40m, Distance covered by Arnab in one round of the park, , = The perimeter of the park (2(/ + b)] (Put the values and solve), = 2(60 + 40) = 200m, , Distance covered by Arnab in 10 rounds of the park, every day = 200 » 10 = 2000 m, , 2000, = (2202 km =2km (° 1 km = 1,000 m), , soluti, , , , 1000, ‘Ans: So, Arnab covers a distance of 2 km per day while jogging in the park., , RA Exercise @, , 4. if the length of one side of a square is 9 cm, then find the perimeter of the square. 2, 2. Find the length of a side of a square if the perimeter is 36 m. &,, 3. Find the cost of fencing a square park of side 200 m at the rate of %25 per metre. 4, 4. Find the perimeter of the following rectangles with the following measurements. @, a. length = 10 m, breadth = 5m b. length = 120 mm, breadth = 40 mm, c. length = 320cm, breadth = 100 cm d. length = 150 m, breadth = 30m, 5. Find the breadth of the rectangle of perimeter 120 cm and the length of the following measures., a. 50cm b. 15cm c. 42cm d. 25.5cm, , 6. Sarita wants to paste a coloured tape all along the border of a rectangular chart paper of length 100 cm, and breadth 80 cm. What should be the length of the tape?, , 7. A rectangular park has a walking track of length 800 m and breadth 520 m. If Shraddha takes two, rounds of the park, then how much distance does she cover?, , 8. Sudesh has made a wooden rectangular table top of perimeter 12 m. If the length of the table top is, 3.4 m, then what is its breadth?, , 9. A rectangular track has dimensions 650 m by 200 m. How many rounds of this track will the toy train, take if it has to travel 3.4 km?, , 10. The dimensions of a rectangular pathway is 350 m by 150 m. A boy cycles around it at the rate of 6 km, , per hour. In what time will he complete 5 rounds?, , High Order Thinking Skills, , 1. Jaya runs around a square park of side 410 m. Bulbul runs around a rectangular park of length 100 m and, breadth 50 m. Who covers more distance and by how much?

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ae, , ?, , 2. Jai builds a square of side 15 cm from a wire. If from the same wire, he builds a rectangle of width 10 the, what is the length of the rectangle?, , 3. The width and the length of a rectangle are two consecutive numbers. If the perimeter is 30 cm, then whey., its width?, , 4. Arectangular park has length of 30 meters and width of 15 meters. If trees are planted along its Sides wit, ., , gap of 2 meters, then how many trees can be planted?, A _30m B, , , , , , D E, , 5. Ram runs around a square park of 100 m and Mohan runs around a rectangular park with length of 1504., and breadth of 100 dm. Both takes 5 rounds of the parks, they move around. Find which of them runs Motz, distance and by how much., , 6. Find the cost of fencing a garden whose length and breadth are 50 m and 15 m, respectively. The vendor hac, submitted the commercials as 12 per cm., , 7. The length and breadth of a rectangular field are in the ratio of 5 : 3. If the perimeter of the field is 16007., find the length and breadth of the field in dm., , 8. Ram Kumar wants to do fencing around his square field to protect the crops from the animals. The side of tt:, field is 90 m. Rahim and Karim are two vendors who quoted Ram Kumar the cost of fencing. Rahim quotec, ~200 per m and Karim quoted 2 20 per dm. Find who is charging more for the same work., , 9. The dimensions of a photograph is 20 cm x 15 cm. The paper on which the photo is to be printed is c’, dimensions 25 cm x 20 cm. Find the ratio of their dimensions., , , , , Perimeter of Ee, , , , adv, , , , The measure of the boundary of a polygon is called its perimeter. E, , Let us find the perimeter of the given pentagon. The perimeter will be the sum of length, of all its sides., , Therefore, the perimeter of pentagon ABCDE is AB + BC + CD + DE + EA san \", =1cm+2cm+2cem+4cm+3cm, Ans: Perimeter = 12 cm A, 1cm, Perimeter of Regular Polygons B ‘ ao, cm, A regular polygon has all the sides of equal length and all the angles of equal measure. c, We know that a square is a regular polygon with four equal sides. Fig 14.3: A polyso”, , [he perimeter of a regular polygon with n number of sides of length /units = nx /units, , Perimeter of a regular polygon with n sides = nx side, , , , , he following table shows the perimeter of the regular polygons.

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Example 16: Find the cost of fencing a regular pentagonal park with each side of length 200 m at the Fate of 29, , per metre., Solution: Perimeter of the park = 5 x length of each side = 5 x 200m = 1 ,000 m, Cost of fencing = perimeter x cost per metre, = 1,000 x 20 = 20,000, , Ans: Thus, the cost of fencing the park is ¥ 20,000., , , , 1. If the length of one side is 9 cm, then find the perimeter of the following., b. aregular pentagon, , a. an equilateral triangle, d. arhombus, , c. aregula hexagon, 2. Find the length of a side of:, a. an equilateral triangle if the perimeter is 27 mm., Find the length of the equal sides of an isosceles triangle of perimeter 65 cm and an unequal side of, , b. a regular pentagon if the perimeter is 40 cm., , measure 25 cm., 4. Calculate the perimeter of the folowing figures., , im, , , , , , , , , , , , , , Perimeter = Perimeter = Perimeter=_ sm, d. ft, 6ft ek s 6%em, 2% em, 4ft 4cm, 4ft, 7 ft, Perimeter = ft Perimeter = cm 2, 5. A square has a perimeter of 24 cm. Equilateral triangles are constructed, around its boundary (see the figure given below). If an ant crawls along ¢ é, ABCDEFGHA, then what distance is covered by the ant? : F, A G, 6. Find the perimeter of the following figures and convert them in the, mentioned units., H, , a. In metres b. In millimetres, , , , A 5.5m B

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Pr, , c. Indecimetres d. In millimetres, , A 10cm, , D, acm \2em, P c 2cm, F, ren 2em = pe, a-—> 8, 2cm, D 2am ©, , 7, Find the perimeter of a regular octagon whose side is 12 cm,, , , , , , , , 4, Find the side of a regular heptagon in dm if the perimeter of the heptagon is 133 m, , The landscape of gardens a e given below. Which garden will require the larger fencing around, and what will be the total cost of fencing of both the gardens if the cost of fencing is 80 per meter?, GardenA Garden B, , 5m 2em gem, 7cm, — gem, 5cm 6cm, 11cm, 3cm, , 40. Arectangular field is having length and breadth as 0.3 km and 0.1 km. Each side is to be fenced with 3, rows of wires. What is the length of the wire needed in metres?, , Multiple Choice Questions, , Tick (“) the correct option., a. The perimeter of a triangle with sides of measure 6 cm, 10 cm and 14 cm is, , , , i, 29cm () ii, 34m () iii. 30cm ( iv. 60cm O, b. Aregular hexagonal table top has each side of length 1 m 50 cm. The perimeter is ¥, , i, 5em {) ii, 6cm (2) iii. 7em () iv. 8cm oO, c Apiece of string is 72 cm long. Find the length of each side if it is bent to form an equilateral triangle., , ar) () ii. 20 () ii, 24 (0 wv. 26 O, , , , Anand is painting the walls of his room. In order to get some idea of how much paint he requires, he needs to, know the amount of space covered by the walls of his room. The amount of space covered by any closed figure is, known as the area., , The amount of surface enclosed by a closed figure is called the area of that figure., , Look at the figure 14. 6. In all the cases, fig. (i) is bigger than fig. (ii). So, fig (i) will occupy a larger space than figure, (i). We can, therefore, say that the area of figures (i) is more than the area of figures (ii)., , Oo [JO @or, , @ (ii) wi (ii) (i) (ii) (i) (ii), , , , , , Fig 14.6: Area enclosed by shapes

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Scene of the square = 4 x side, , . 4xs=196 >s=49m, So, the area of the square courtyard = s xs = 49 x 49 = 2401m?, Cost of cementing at the rate of 75 perm? = 2401 x5 = 12005, Example 28: What is the width of a rectangle with perimeter 153.6 m and length 49.5 m?, , , , Solution: Let the width of the rectangle be b meter., Perimeter of the rectangle = 2(/ + 6), => 2(b + 49.5) = 153.6, => 2b+ 99 = 153.6, => 2b=54.6, => b=27.3m, Ans: So, the breadth of the rectangle is 27.3 m., , eS, s\n \ Exercise, , 1. Find the areas of the following figures by counting squares., b. 1 Jt 1, , , , , , , , , , , , a, , , , , , , , , , , , , , , , , , , , , , , , 2. Find the area of the following figures., a. b., , 20m 30cm, , , , , , , , 50m 30cm, , 12cm, 3. Find the area of a square handkerchief of side 30 cm., 4. The area of a rectangular frame is 875 sq. cm. If its width is 25 cm, then what is its length?, 5. Find the length of the sides of the following squares if its area is:, , b. 121 sq.cm, , a. 81sq.m, 6. How many square tiles of side 4 cm can be fixed on a surface of length 36 cm and breadth 16 cm?, , 7. The area of a rectangular garden 49 m long is 441 sq. m. Find the width of the garden