How do u do question 27 and 29. find the measure of angle x?

For 27, check the left-side of the picture below.

the arc has 88°, and therefore the central angle also has 88°.

notice the red tickmarks, since those two segments are radius, they are equal, that makes an isosceles triangle, with a "vertex" of 88°, and twin sides on the "bases".

so 180 - 88 is 92, and since "x" and the other angle are twins, 92/2 is "x".

for 29, check the right-side of the picture below.

"x" is sitting on a flat-line that runs through the center of the circle, and therefore that line is the diameter, now, a flat-line is always 180°.

we know the arc there is 130°, so, the arc of the area where "x" is at is 180° - 130°, now, that arc is the "intercepted arc" from an "inscribed angle".

by the "inscribed angle theorem" that you see there below, "x" is half that arc.

It would be the second one because it passes the vertical line test

21/2 or 5/2