Question 1073694
<pre>

180° < A < 270° is the third quadrant.

We first find the reference angle, which is the angle
whose sine is +5/7.

On your TI-84, press 2ND SIN then press 5/7) ENTER

Read 45.5846914°, which is the reference angle. To
increase it to the desired angle in QIII, we add 180°:

A = 225.5846914°

Edwin</pre>