Explain why the value of sine ratio for an acute angle of a right triangle must always be a positive value less than 1

Answer: See below.

The sine ratio is the ratio of the opposite side over the hypotenuse in a right triangle. The hypotenuse is always the largest side of a triangle.

Therefore, the denominator will always be the largest. If the denominator is larger than the numerator, it will be a number less than one.

And it will be positive because it is an acute angle so the triangle when plotting in the unit circle would only be in the first quadrant. All values in the first quadrant are positive.