Quadrilateral abcd is inscribed in this circle. what is the measure of angle c?

Which ahows the graph of the solution set of 6x+4y< 12

White shapes and black shapes are used in a game. some of the shapes are circles. while the rest are squares. the ratio of the number of white shapes to the number of black shapes is 5: 11. the ratio of the number of white cicrles to the number of white squares is 3: 7. the ratio of the number of black circles to the number of black squres is 3: 8. work out what fraction of all the shapes are circles.

Either enter an exact answer in terms of \piπ or use 3.143.14 for \piπ and enter your answer as a decimal.