annulus problem 2:
An annulus has a larger circle radius R of 14 cm and a smaller circle radius r of 8 cm.
a) calculate the area of the circle sector
b) calculate the the perimeter/circumference of the circle sector
area:
convert diameter to radius
oudside radius (R): 84 mm : 2 = 42 mm
inside radius (r): 68 mm : 2 = 34 mm
answer area
area = π * (R² – r²)
area = π * (42² – 34²)
area = 1 910.09 mm²
A: The area of the circle sector is 1 910.09 square millimeter.