Someone help with this please

The radius of the circle is 4 cm and the measure of the central angle is 90° the area of the sector with a central angle measuring 90° and radius of length 4 cm is vt cm the triangle in the sector is 4 cm the area of the triangle is v/cm² the area of the segment of the circle is (471 - ) cm?

The owner of the plant nursery where you were tells you to fill 350 ml bottles from a 30 l from a fertilizer

How can you find the mean absolute deviation (mad) for this set of data?