Jawab dengan benar ya

3.
DE / CE = AB / BC
DE / 8 = 5 / 12
DE = 5/12 x 8
DE = 40 / 12
DE = 10/3 cm

4.a)
AB² = AD x AC
20² = 16 x (AD + CD)
400 = 16 x (16 + CD)
400 = 256 + 16CD
16CD = 400 - 256
16CD = 144
CD = 144 / 16
CD = 9cm

b)
BC² = CD x AC
BC² = 9 x (16 + 9)
BC² = 9 x 25
BC² = 225
BC = √225
BC = 15 cm

c)
BD² = AD x CD
BD² = 16 x 9
BD² = 144
BD = √144
BD = 12 cm

d)
L = 1/2 x cd x bd
L = 1/2 x 9 x 12
L = 54 cm²