pakai cara!!!!! nomor 11

L.trapesium ABED = 1/2 x (AB+DE) x BE
300 = 1/2 x (16 + 24) x t
300 = 1/2 x 40 x t
300 = 20t
t = 300/20 = 15

EC = √25^2-15^2 =√625-225=√400=20

jadi panjang CD = 24+20=44
L.trapesium ABCD adalah
=1/2 x (44+16) x 15
=1/2 x (60) x 15
=30 x 15
= 450 cm^2

L ABED + L BCE
= 300 + (1/2 a x t)

t= 300 : (24 + 16) x2
 = 15 cm

a BCE= √25² - 15²
           = √625 - 225
           = √400
            = 20 cm

L BCE= 1/2 20 x 15
          = 150 cm²
           = 300 + 150 = b. 450 cm²