The cone is cut off along de a 6 cm a find the base

The cone is cut off
along DE.
A
6 cm
(a) Find the base radius of the smaller cone. (4 marks)
(b) Find the total surface area of the solid frustum (6 marks)
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22) The figure below shows two circles of radii 8cm and 6cm with centres O
1
and O
2
respectively.
The two circles intersect at points A and B. The lines O
1
O
2
and AB are perpendicular to each
other. If the common chord AB is 9cm, calculate the area of the shaded region. (10 marks)
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23) A room is to be constructed such that its external length and breadth are 7.5m and 5.3 m
respectively. The thickness of the wall is 15cm and its height is 3.3 m. A total space of 5m
3
is to
be left out in the walls for a door and windows.
(a) Calculate the volume of the material needed to construct the walls without the door and the
windows. (5 marks)
(b) The blocks used in constructing the walls are 45cm x 20cm x 15cm. 0.225m 3 of cement
mixture is used to join the be blocks. Calculate the number of blocks needed to construct the
room. (5 marks)
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24) Two flag-posts of equal height h metres are 100m a part. At a point x between the posts, the
angles of elevation of the tops of the flag posts are 46
0
and 40
0
respectively. Write down two
equations for h and solve the equation to find the value of h. (10 marks)
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