If s denotes the length of the arc of a circle of radius r subtended by a central angle ,
find the missing quantity.
rafeet, s = 21 feet, e = ?

If the measure of angle 1 is 110 degrees and the measure of angle 3 is (2 x+10 degree), what is the value of x?

Find the number of real number solutions for the equation. x2 + 5x + 7 = 0 0 cannot be determined 1 2

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.