Help me please I'm really confused ​

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?

Average acceleration: i have no idea how to do this.

Divide. reduce the answer to lowest terms.5 2/3 ÷ 3 1/9