tolong dong kak buat besok :)

BC = PQ = 20 cm

AC² = BC² - AB²
       = 20² - 16²
       = 400 - 256
       = 144
AC = √144
AC = 12 cm

L ABC = 1/2 x AB x AC
           = 1/2 x 16 x 12
           = 96 cm²