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AMC 12/AHSME
1985 AMC 12/AHSME
2
2
Part of
1985 AMC 12/AHSME
Problems
(1)
Shape of a Monster
Source:
3/2/2009
In an arcade game, the "monster" is the shaded sector of a circle of radius
1
1
1
cm, as shown in the figure. The missing piece (the mouth) has central angle
6
0
∘
60^{\circ}
6
0
∘
. What is the perimeter of the monster in cm?[asy]size(100); defaultpen(linewidth(0.7)); filldraw(Arc(origin,1,30,330)--dir(330)--origin--dir(30)--cycle, yellow, black); label("1", (sqrt(3)/4, 1/4), NW); label("
6
0
∘
60^\circ
6
0
∘
", (1,0)); [/asy]
(A)
\ \pi \plus{} 2 \qquad
(B)
\ 2\pi \qquad
(C)
\ \frac53 \pi \qquad
(D)
\ \frac56 \pi \plus{} 2 \qquad
(E)
\ \frac53 \pi \plus{} 2
geometry
perimeter