What are the root(s) of the quadratic equation whose related function is graphed below?

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.°

The area (a) of a circle with a radius of r is given by the formula and its diameter (d) is given by d=2r. arrange the equations in the correct sequence to rewrite the formula for diameter in terms of the area of the circle.

Im so bad at fractions they are not my best math thing to work on