How much of a circle does a 100 degree angle turn through ​

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.°

Megan is making bracelets to sell to earn money for the local animal shelter. it takes her 1/4 hour to pick out all the beads and 1/10 hour to string them.this week, she only has 5 1/4 hours to make bracelets. how many bracelets will megan be able to make?

Perform the indicated operation and write the answer in the form a + bi. (-5 + 2) + (3 - 6i)