Someone pls help me ill give out brainliest pls don’t answer if you don’t know

Suppose the radius of a circle is 16. what issuppose the radius of a circle is 16. what is its circumference its circumference

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.°

Keith runs 5 miles in 38 minutes. at the same rate, how many miles would he run in 57 minutes