Page 199 - Mathematics_Form_Two
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Trigonometry
Find: What width of the river did Anna
(a) The width of the river. obtain?
(b) The height of the coconut tree 16. Two boats, A and B are due south of a
if the angle of elevation of the
top of the coconut tree is 22° cliff. The two boats are 890 m apart.
from A. The angles of elevation at the top of
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(c) The angle of elevation of the the cliff of the two points A and B
top of the coconut tree from B. are 26º14¢ and 17º56¢, respectively.
(d) The distance from B to the top Find the height of the cliff.
of the coconut tree. 17. A boat at point R is observed from two Mathematics for Secondary Schools
13. A ladder of length 12 m leans points P and Q which are 3 km apart
against a vertical wall.
as shown in the following figure. If
(a) If it makes an angle of 28º with PQR = = 84° and PQR = = 67°, find:
!
!
67º
67º
the wall, how far up the wall
does it reach? (a) PR
(b) If it reaches 10 m up the wall, (b) QR
what angle does it make with
the horizontal?
14. Juma notices that the angle of
elevation of the top of a mango
tree is 32º. Walking 11 metres in
a direction towards the tree he
observes that the angle of elevation 18. A railway signal SP is supported by
is 45º. Find the height of the tree. two chains SQ and SR of length 6
15. Anna wishes to find the width XY m and 9m, respectively as shown
of the river as shown in the following in the following figure. If the angle
figure. She measures a distance AB of elevation of the top of the signal
= 100 m along the bank of the river. from point Q is 48°, find:
!
She observes that a point X on the (a) SRQ .
other bank of the river is such that (b) The distance QR.
ˆ
ˆ
XAB = 49º and XBA = 58º. (c) The height of the signal SP.
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Student's Book Form Two
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MATHEMATIC F2 v5.indd 193 11/10/2024 20:14:24
MATHEMATIC F2 v5.indd 193
