Determine whether the statement is sometimes, always or never true. if ax+b-4=b and a is not equivalent to 0 then then x = 4/a

With these 5 geometry questions! pls 1.)quadrilateral abcd is inscribed in this circle.what is the measure of ∠a ? enter your answer in the box.°2.)quadrilateral abcd is inscribed in a circle.what is the measure of angle a? enter your answer in the box.m∠a= 3.)quadrilateral abcd is inscribed in this circle.what is the measure of angle b? enter your answer in the box.m∠b= °4.)quadrilateral abcd is inscribed in this circle.what is the measure of angle a? enter your answer in the box.°5.) quadrilateral abcd is inscribed in this circle.what is the measure of angle c? enter your answer in the box.°