√ 19 + 6^2 ÷ 7.2^2 I need help ASAP

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?

Table which ratio is equivalent to 3: 7? 6: 7 3: 21 24: 56 15: 30

What percent of 18 is 24? and plz explain thx.