Answer:
0.68
Explanation:
p(white area) = (white area)/(total area of the circle)
The white area is the area of the triangle subtracted from the total area of the circle.
area of circle = (pi)r^2 = pi * (4 cm)^2 = 16(pi) cm^2 = 50.265 cm^2
area of grey triangle = (1/2)bh
The base is a diameter of the circle, so it is twice the radius.
The height is a radius.
area of grey triangle = (1/2)bh = 0.5 * 8 cm * 4 cm = 16 cm^2
white area = area of circle - grey area = 50.265 cm^2 - 16 cm^2 = 34.265 cm^2
p(white area) = (white area)/(total area of the circle)
p(white area) = (34.265 cm^2)/(50.265 cm^2)
p(white area) = 0.68