20 points! find the measure of angle x. find the value of x.

In the first figure we have an angle that subtends a diameter.  Those are always right angles, so

x=90 degrees

In the second figure we have to notice that the measure of arcs and central angles are interchangeable -- the measure of an arc is its central angle.

The units are implicitly degrees; the 10 should say 10°

These are supplementary angles so they add to 180°

3x + (7x + 10) = 180

10x = 170

x = 17

x=17

17° would be more accurate but the units are a bit ambiguous here so I'll leave it.

step-by-step explanation:

1     sepan

2     encuentren

3     tenga

4     hable

5   parezca

6   llegue