Question

Example 4: Find the length of AC? D A 65° 12cm 7cm B​
topic: trigonometry

Answer 1

13.14cm

Explanation:

lets start by finding the length of AD

90 + 65=155...........180-155= 25

x/sin 25= 7/sin 90

xsin90=7sin 25

x= 2.96cm=AD

Now lets find DC

we shall find DB first;

x/sin65=7/sin90

xsin90=7sin65

x=6.34cm...=DB

Now lets use Pythagoras theorem to find DC

12²-6.34²=√103.80

DC=10.18cm

Add AD and DC

2.96+10.18= 13.14cm

AC=13.14cm

Answer 2

Explanation:

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