扇形半徑！fast！

1.全部人都計錯sa!首先,let the radius be r cm,
150度/360度x(2r)x(3.14)=6
5/12x(2r)x(3.14)=6
r=6x(12/10x3.14)
r=2.291831181cm

2.let the radius be r cm,
43度/360度x(2r)x(3.14)=3.5
r=3.5x(360/86x3.14)
r=4.66360996cm

1.OAB,角度150度,AB 6cm,要半徑！
2.29(cor. to 3 sig.fig)

2.AOB,角43,AB(弧度)3.5cm！
4.66(cor. to 3 sig.fig)

1.設半徑為r
150/360x2r3.1415927=150
2r3.1415927=360
2r =114.591559
r =57.2957795
所以半徑是57.3cm



2.設半徑為r
43/360x2r3.1415927=3.5
2r3.1415927=29.3023256
2r=9.32721992
r=4.66360996
所以半徑是4.66cm

1st quetion :OAB 的圖係咪A╭─╮B
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