YEAR 9
UNIT 9
TRIGONOMETRY
REVIEW OF PYTHAGORAS
LI: We are learning about Trigonometry.
SC: I can understand Pythagoras’ theorem.
EXAMPLE 1
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EXAMPLE 2
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Complete Exercise 4A (page 152): questions
FINDING THE LENGTH OF THE HYPOTENUSE
LI: We are learning about Trigonometry.
SC: I can find the length of the Hypotenuse.
EXAMPLE 1
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EXAMPLE 2
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EXAMPLE 3
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Find the length of the hypotenuse in each of the following. Set out your work as shown in the
examples. (All dimensions are in cm.). Questions 1, 2, 3 and 4 have been started for you.
1. y 2 = 12 2 + 5 2 2. c 2 = 6 2 + ___ 2
y 2 = ____ + ____ c 2 = 36 + ____
y = _____ c = _____
y = _____ cm c = _____ cm
3. q 2 = ____ 2 + ____ 2 4. _ 2 = ____ 2 + ____ 2
q 2 = ____ + ____ _ 2 = ____ + ____
q = _____ _ = _____
q = _____ cm _ = _____ cm
5. 6.
7. 8.
Show the working to these in your book:
FINDING THE SHORTER SIDE
LI: We are learning about Trigonometry.
SC: I can find the length of the shorter side.
EXAMPLE 1
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EXAMPLE 2
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EXAMPLE 3
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Find b correct to 1 decimal place if necessary. Set out your work as shown in the examples. (All
dimensions are in cm.). Questions 1, 2, 3 and 4 have been started for you.
1. 2.
132 = b 2 + 12 2 10 2 = b 2 + 8 2
169 = b 2 + 144 100 = b 2 + ____
169 − ____ = b 2 100 − ____ = b 2
____ = b 2 ____ = b 2
b = _____ b = _____
b = _____ cm b = _____ cm
3. 17 2 = b 2 + ____ 2 4. ____ 2 = b 2 + ____ 2
289 = b 2 + ____ ____ = b 2 + ____
____ − ____ = b 2 ____ − ____ = b 2
____ = b 2 ____ = b 2
b = _____ b = _____
b = _____ cm b = _____ cm
5. 6.
7. 8.
Show the working to these in your book:
LABELLING ANGLES
LI: We are learning about Trigonometry.
SC: I am able to label the sides of a right-angled triangle with respect to a given angle and define the
trigonometric ratios.
EXAMPLE 1
EXAMPLE 2
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Complete Exercise 4E (page 171): questions
FINDING UNKNOWN SIDES
LI: We are learning about Trigonometry.
SC: I can find the length of an unknown side in a right-angled triangle.
EXAMPLE 1
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EXAMPLE 2
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EXAMPLE 3
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Complete Exercise 4F: questions
FINDING UNKNOWN SIDES IN THE DENOMINATOR
LI: We are learning about Trigonometry.
SC: I can find the length of an unknown side in a right-angled triangle.
EXAMPLE 1
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EXAMPLE 2
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EXAMPLE 3
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Complete Exercise 4G (page 181): questions
FINDING UNKNOWN ANGLES
LI: We are learning about Trigonometry.
SC: I can find the size of an unknown angle in a right-angled triangle.
EXAMPLE 1
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EXAMPLE 2
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EXAMPLE 3
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Complete Exercise 4H (page 187): questions
SOLVING TRIGONOMETRIC PROBLEMS
LI: We are learning about Trigonometry.
SC: I can solve problems with right-angled triangles using trigonometry.
EXAMPLE 1
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EXAMPLE 2
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Complete Exercise 4I (page 191): questions
