[Exercise- page 179]
E.8.1 Each of you to draw some circles of different radii as you like. Measure the radius, diameter and circumference of the circular area. Then fill up the table determining the area by graph paper and formula.
Solution:
E.8.2 Draw the following table on your exercise book and fill in the gaps by calculation
Solution:
E.8.3 Two concentric circles are shown in the side figure. The area of right angle triangle OAB is 18 sq. m.
a) Determine the circumference of small circle.
b) Determine the circumference of big circle.
c) Determine the area of small circle.
d) Determine the area of big circle.
e) Determine the area of green portion.
Solution:
E.8.4 Draw a circle of radius 15 cm. on the back page of an old calendar. Now cut the circular drawing on the calendar. Cut two circular areas of radius 2.5 cm. and a rectangle of length 3.5 cm and width 2 cm. from the circle. Colour the rest as you like. Determine the area of your painted portion.
Solution:
E.8.5 Diameter of a circular park is 25 meters. There is a road with 2 meters width around the park. Determine the area of the park.
Solution:
E.8.6 Cut a circular area of radius 6 cm from a paper drawing. Now, cut four circular areas of radius 5 cm.
Now, colouring small circles as you like, set them inside the big circle with glue like the above figure. Then draw the following table on your exercise book and fill up the blanks.
Solution:
E.8.7 Fatin went to a pizza shop with her elder sister Lamia to buy pizza. They found two packages in the price list hanging in the shop. The height of pizza in both packages is equal.
a. One pair of pizza with diameter of 35 cm. costs 300 tk.
b. Three pizzas with diameter of 30 cm. cost 350 tk. Which package will be the best for Fatin and Lamia?
Solution:
E.8.8 Demonstration of circular bodies and detailed account project: Divide all students in some groups. Measure radius, diameter, circumference and area of familiar circular objects of daily life. Discuss with other groups.
Solution:
E.8.9 Nitu likes to embroider handkerchief, napkin, cushion or, any cloth using different yarns. She makes different designs using needle-yam in her leisure time. The radius of the circular disc (Embroidery hoop), which is used by Nitu is 15 centimeter.
a) Determine the area of the disc.
b) Determine the area of cloth inside disc.
Solution:
No comments:
Post a Comment