Step-by-step explanation:
Given that,
A motor boat travels 60 miles down a river in 3 hours but takes 5 hours to return upstream,
We know that,
Speed = distance/time
The rate while moving downstream
The rate while moving upstream
The rate of the boat in still water is the average of these:
The rate of the current is the difference between the boat speed and actual speed = 16 mph - 12 mph = 4 mph
Hence, this is the required solution.
Answer:
m∠BAC=45°
Step-by-step explanation:
Firs we graph the given points to see the shape of triangle.
We can clearly see that triangle BAC is a right angle triangle whose sides BA and BC both are equal to 4 units.
We know that equal sides of triangle corresponds to equal angles.
Hence
∠A = ∠C ...(i)
We know that sum of all three angles of a triangle is 180°. So we can write
∠A + ∠B + ∠C=180°
∠A + ∠B + ∠A=180° {from (i) }
∠A + 90° + ∠A=180° {∠B is right angle}
2∠A + 90° =180°
2∠A = 90°
divide both siide by 2
∠A = 45°
∠A and ∠BAC are same
Hence
m∠BAC=45°
