Whats the formula for arithmetic and geometric problems?

A33 gram sample of a substance that's used to detect explosives has a k-value of 0.1473. n = noekt no = initial mass (at time t = 0) n = mass at time t k = a positive constant that depends on the substance itself and on the units used to measure time t = time, in days

Which of these tools or constructions is used to inscribe a hexagon inside a circle?

Plz hurry evaluate the expression a+b where a=8 and b=19