Asap quadrilateral abcd is inscribed in a circle.
what is the measure of angle a?

Since the two given angles, angle C and angle A, are across from each other inside the quadrilateral, that means that they add to 180 degrees
A + C = 180
2x + 9 + 3x + 1 = 180
combine like terms
5x + 10 = 180
subtract 10
5x = 170
divide both sides by 5
x = 35

Angle A is (2x + 9)
2(35) + 9
70+9
Angle A is 79 degrees.

Hope this helps!

They are somewhat similar

M< 5 = 80 , < 2 = 80, < 6= 100, < 3= 100, < 7= 80, < 4= 80, < 8= 100