Answer:
Step-by-step explanation:
strategy: Find the area of the entire dartboard, then subtracted the inner circle from that whole. we will have the entire outer circle, so divide that by 2 for half of it. Next divide the inner circle by 4 . Then add that to the outer circle answer from above.
whole circle = [tex]\pi[/tex]*[tex]20^{2}[/tex] = 1257.142857 [tex]cm^{2}[/tex]
inner circle = [tex]\pi[/tex]*[tex]10^{2}[/tex] = 314.2857143 [tex]cm^{2}[/tex]
1257.142857 - 314.2857143 = 942.8571427 outer circle
942.8571427 / 2 = 471.4285 ( half of the outer circle)
now find quarter of the inner circle
314.2857143 / 4 = 78.57142855
add the two parts together
78.57142855 + 471.4285 = 549.9999
The shaded regions = 550 [tex]cm^{2}[/tex]
