Help on 15 and 16 its geometry!!

Step-by-step explanation:

15. If A and B are complementary angles, then sin A = cos B and cos A = sin B.

So if sin A = m, then cos B = m.

16. If sin A = cos B, or cos A = sin B, and A and B are acute, then A and B are complementary.

a. cos 60° = sin θ

60° + θ = 90°

θ = 30°

b. sin 71° = cos θ

71° + θ = 90°

θ = 19°

c. sin θ = cos (θ + 20°)

θ + θ + 20° = 90°

2θ = 70°

θ = 35°

d. sin (θ − 60°) = cos θ

θ + θ − 60° = 90°

2θ = 150°

θ = 75°

36

step-by-step explanation:

54 km / hours

step-by-step explanation:

we need to convert seconds to hours

60 seconds = 1 minutes

60 minutes = 1hour

15 m         60 second   60 minutes

  * *         = 54000 meters/ hour

second     1 minute             1 hour

now we need to convert meters to km

1000 m = 1 km

54000 m       1 km

*   = 54 km / hours

hour               1000m