find the sine of angle B

The answer to your question is sin Ф = 4/5  

Step-by-step explanation:

From the picture, we know that ∠C is a right angle, so ΔABC is a right triangle.

To solve this question use trigonometric functions

    sin Ф = Opposite side / hypotenuse

Opposite side = 4

Hypotenuse = 5

Then,

        sin Ф = 4/5    

Step-by-step explanation:

Triangle ABC is a right angle triangle.

From the given right angle triangle,

AB represents the hypotenuse of the right angle triangle.

With m∠B as the reference angle,

BC represents the adjacent side of the right angle triangle.

AC represents the opposite side of the right angle triangle.

To determine Sine ∠B, we would apply the Sine trigonometric ratio.

Sin θ = opposite side/adjacent side. Therefore,

Sin B = 4/5 =

SinB = 0.8