Equation of a circle.
Pls help!!!

Two sides of a triangle mesure 20cm and 30cm. what is the measure of the third side

The table below shows the height of a ball  x  seconds after being kicked.  what values, rounded to the nearest whole number, complete the quadratic regression equation that models the data? f(x)  =  x2  +  x  +  0based on the regression equation and rounded to the nearest whole number, what is the estimated height after 0.25 seconds?   feet

Ben is three times as old as samantha, who is two years older than half of michel's age. if michel is 12. how old is ben?