We are given
△ABC, m∠A=60° m∠C=45°, AB=8
Firstly, we will find all angles and sides
Calculation of angle B:
we know that sum of all angles is 180
m∠A+ m∠B+m∠C=180
we can plug values
60°+ m∠B+45°=180
m∠B=75°
Calculation of BC:
we can use law of sines
now, we can plug values
Calculation of AC:
now, we can plug values
Perimeter:
we can plug values
Area:
we can use formula
now, we can plug values
...............Answer
Answer:
<h2>B. The amount of fuel used was lowest at speeds around 60km/h.</h2>Step-by-step explanation:
The decreasing part is from (20,13) to (60,6), which gives an average rate of
Then, we have an increasing part from (60,6) to (120,10), which gives an average rate of
Basically, at 60 km/h the fuel used was 6 liters per 100 kilometers. Notice that the other velocities make the car to use more liters per kilometers.
Therefore, the amount of fuel used was lowest at speeds around 60 km/h.
