Answer:
Part A
You'll travel 8.0 km before you can turn to the north to reach your friend's residence.
Part B
At your friend's house, the sine of the angle θ measures 0.8.
Explanation:
The remaining part of the question including an image is displayed below.
Explanation:
Part A
To calculate how far you'll go before making the northward turn,
the diagram illustrates the length of your street.
Let the length of your street correspond to 
and your friend's street length be denoted as 
with the distance separating your house from your friend's indicated as
.
The diagram illustrates a right triangle.
The sides of this triangle can be represented by
and
.
To identify
, the extent of your street,
we can apply the Pythagorean theorem: 'The area of the hypotenuse equals the total of the squares of the other two sides.'
This leads to:

Here,
represents the hypotenuse, which is the distance between your house and your friend’s house,
thus, 
indicates the adjacent side, which is your friend's street distance.
Furthermore, 
and
represents the opposite side, corresponding to your house's distance.
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Then, 


Therefore, you need to ride 8.0 km before turning north to reach your friend's house.
Part B
In order to calculate the sine of the angle θ at your friend’s location,
the diagram indicates that the sine of angle θ can be expressed as

Consequently, 
Then,


Thus, the sine value at your friend's house is 0.8
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