How many angles in a 5 pointed star?

Why was the Chinese number system invented? What is the correct displacement for the following 4km south 2km north5km south5km north? How many kilometers go into 145 meters? What does E 2 mean? Is there any way to solve a system of equations with C and D as constants and x and y as variables sinx plus cozy - C equals 0 cosx plus siny - D equals 0? What is the denominator for the rational number 2? What is the number 72 in roman numerals? Who has a quadrillion dollars? What is the volume of a right circular cone? How can you find out the serial number of a gun you purchased that was stolen and you lost the number? How many days in 2880 minutes? What kind of angle is 109? what is 6x7 equle? Quadrangle with two pairs of equal sides? What does it mean if a TI-83 plus calculator says invalid dim and won't graph anything? What goes into 349 and 72? What is the area of an equilateral triangle with side lengths of 6 inches? What is 14 more than -1? How do you evaluate -b cubed if b is five? When it says .15 how do you write that as a percent?