Question

17. Find the altitude of a triangle whose base and area are 16.4 cm and 246 cm.
18. Find the area of circle whose radius is:
2. 7 cm
b. 3.5 cm
c. 49 cm
19. Find the diameter of a circle whose area is 628 cm. (use n = 3.14).
20. Find the area of square of side 4 cm. If the side of square is doubled, find the area of the resulting new
square.
21. Find the area of rectangle of length I and breadth b. If length is doubled and breadth is halved find the
area of the new rectangle formed. Are the two areas equal?​

Answer 1

Answer:

17. Area of triangle=1/2 (b)(h)

Area=246cm^2

b=16.4pm

246=1/2 (16.4)(h)

246=8.2 (h)

h=246÷8.2

h=30cm

18. Area of circle=4 (pi)r^2

a. Area=4×(22÷7)×7×7

=616cm^2

b. Area=4×(22÷7)×3.5×3.5

=154cm^2

c. Area=4×(22÷7)×49×49

=30184cm^2

19. Area=4×3.14×r^2

628=12.56×r^2

628÷12.56=r^2

r^2=50cm

r=5 root 2 cm