6) What is the radius of the circle if the angle of sector is 90 Degree and the area of the sector is 196 cm²?

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?