7) What is the area of the sector, whose diameter is 40 mm and angle is 120 Degree?

8) What is the length of arc of a sector, whose radius is 15 cm and angle is 40 Degree?

9) What is the length of arc of a sector whose radius is 3.6 cm and angle is 36 Degree?

10) What is the area of the circle, whose diameter is 50 cm?

11) What is the name of the region of a circle between any two point on the circumference?