Chapter 20. Perimeters and Area of Plane Figures
Chapter 20. Perimeters and Area of Plane Figures
Chapter 20. Perimeters and Area of Plane Figures
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
MODULE - 4<br />
Mensuration<br />
Notes<br />
<strong>Perimeters</strong> <strong>and</strong> <strong>Area</strong>s <strong>of</strong> <strong>Plane</strong> <strong>Figures</strong><br />
24. <strong>Area</strong> <strong>of</strong> a triangular field is 2.5 hectares. If one <strong>of</strong> its sides is 250 m, find its corresponding<br />
altitude.<br />
25. A field is in the shape <strong>of</strong> a trapezium <strong>of</strong> parallel sides 11 m <strong>and</strong> 25 m <strong>and</strong> <strong>of</strong> nonparallel<br />
sides 15 m <strong>and</strong> 13 m. Find the cost <strong>of</strong> watering the field at the rate <strong>of</strong> 5 paise<br />
per 500 cm 2 .<br />
26. From a circular disc <strong>of</strong> diameter 8 cm, a square <strong>of</strong> side 1.5 cm is removed. Find the<br />
area <strong>of</strong> the remaining poriton <strong>of</strong> the disc. (Use π = 3.14)<br />
27. Find the area <strong>of</strong> the adjoining figure with the<br />
measurement, as shown. (Use π = 3.14)<br />
2 cm<br />
1.5 cm<br />
6 cm<br />
Fig. <strong>20.</strong>16<br />
28. A farmer buys a circular field at the rate <strong>of</strong> ` 700 per m 2 for ` 316800. Find the<br />
perimeter <strong>of</strong> the field.<br />
29. A horse is tied to a pole at a corner <strong>of</strong> a square field <strong>of</strong> side 12 m by a rope <strong>of</strong> length<br />
3.5 m. Find the area <strong>of</strong> the part <strong>of</strong> the field in which the horse can graze.<br />
30. Find the area <strong>of</strong> the quadrant <strong>of</strong> a circle whose circumference is 44 cm.<br />
1.5 cm<br />
31. In Fig. <strong>20.</strong>17, OAQB is a quadrant <strong>of</strong> a circle<br />
<strong>of</strong> radius 7 cm <strong>and</strong> APB is a semicircle. Find<br />
the area <strong>of</strong> the shaded region.<br />
A<br />
Q. .P<br />
O<br />
Fig. <strong>20.</strong>17<br />
B<br />
32. In Fig <strong>20.</strong>18, radii <strong>of</strong> the two concentric<br />
circles are 7 cm <strong>and</strong> 14 cm <strong>and</strong> ∠AOB =<br />
45 o , Find the area <strong>of</strong> the shaded region<br />
ABCD.<br />
O<br />
45 o<br />
D C<br />
A B<br />
Fig. <strong>20.</strong>18<br />
476<br />
Mathematics Secondary Course
Change language