Jawabanmu

2014-02-23T17:16:08+07:00
A)   AB/DC=AOB/DOC
      AB/22=40/90
      AB= 88/9 cm
b)  90/360. \pi .14^2
     = 1/4 * 22/7 * 14 *14
     = 154 cm^2
c)  154 - 1/2*sin90*14*14
   Sin 90 = 1
   = 154 - 7*14
    = 154 -98
    = 56 cm^2