First we are going to draw our triangle as you can see in the attached image.
Next, we are going to solve it.
To find angle A, we need a trig function that relates the adjacent side with the hypotenuse. That function is cosine, so:
[tex]cosA= \frac{adjacent.side}{hypotenuse} [/tex]
[tex]cosA= \frac{20}{21} [/tex]
[tex]A=arccos( \frac{20}{21} )[/tex]
[tex]A=17.75[/tex]
We can conclude that the measure of angle A is 17.75°.
Now, to find angle B we can use the fact that the sum of the interior angles of a triangle is always 180°:
[tex]B=180-(90+17.75)[/tex]
[tex]B=180-107.75[/tex]
[tex]B=72.25[/tex]
We can conclude that the measure of angle B is 72.25°.
