Jawabanmu

2014-03-27T11:31:40+07:00
Diketahui :
sudut APD = 120^{o}
sudut BPC = 45^{o}
luas BPC = 157 cm^{2}

b. Panjang PB
luas BPC =  \frac{45}{360} .  \pi .  r^{2}
        157 =  \frac{1}{8} .  \frac{22}{7}  . r^{2}
        157 =  \frac{22}{56}   . r^{2}
       8792 = 22 .  r^{2}
       400 =  r^{2}
         r = 20 cm

a. luas lingkaran
=  \pi . r^{2}
=  \frac{22}{7} .  20^{2}
= 1257 cm ^{2}

c. pangjang busur BC
=  \frac{45}{360} . 2 .  \pi  . r
=  \frac{1}{8} . 2. \frac{22}{7} . 20
= 15,7 cm

d. panjang busur AD
=  \frac{120}{360} . 2 .  \pi  . r
=  \frac{1}{3} . 2 . \frac{22}{7} . 20
= 41,9 cm

semoga membantu :) jadikan yang terbaik ya :))







2014-03-27T11:39:38+07:00
B. 157/3,14*360/45=Rkdrt
400=r kdrt
r=_/400=20cm
a.20*20*3,14=1256cm kdrt
c.45/360*2*20=40/8=5*3,14=15,7cm
d. 120/360*2*20=40/3*3,14=41,86cm