Question

Luas segitiga ABCD.......

Answer 1

Dik : 
AB = 12 
AD = 20
BC = 5
CD = 8

maka :
Luas ABC
AC² = 12² - 5²
AC² = 144-25
AC  = 10,90 CM
LABC = 1/2 x 5 x 10,90
          = 27,25 cm²

Luas ACD = 
AC² = AD² - CD²
AC² = 20² - 8²
AC² = 400 - 64
AC  = √336 
AC  = 18,33 CM
LACD = 1/2 x 8 x 18,33
         = 73,32 cm

LABCD = 27,25 + 73,32 = 100,57 CM²