Trigonometrical Ratios

[IloveManUtd]

In my question:

Given that tan A= -3/4 and that A lies between 90 degrees and 270 degrees, find the value of sin A without using the calculator

I know that it lies in the 2nd quadrant and that the adjacent line is 4 while the opposite line is -3. But why is it that the answer for sin A is 3/5 while I get -3/5? Why is it that the hypotenuse is negative 5 and not 5? I really do not understand this. Please help. Thx.

 

[mmm4444bot]

I know that it lies in the 2nd quadrant and that the adjacent line is 4 while the opposite line is -3. Switch your signs.

In Quadrant II, x is negative and y is positive.

Why is it that the hypotenuse is negative 5 Hypotenuse is always positive.

Did you draw a sketch, to visualize angle A?

Opposite: 3
Adjacent: -4
Hypotenuse: 5