ayo dijawab yang bisa

sorry tak pakai cara .ini juga perkiraan semoga dapat membantu
a. AE = 12 cm
b. AS = 6 cm
c. BC = 9 cm
d. DE = 3 cm

1.
DE = 3
BC = 12
EC = 6
AC = AE + EC

AE : AC = DE : BC
AE/AC = DE/BC
AE/(AE + EC) = DE/BC
AE/(AE + 6) = 3/12
AE/(AE + 6) = 1/4
kali silang
4AE = AE + 6
4AE - AE = 6
3AE = 6
AE = 6/3
AE = 2

2.
DE = 2
BC = 3
AT = 15 cm

AS : AT = DE : BC
AS/AT = DE/BC
AS/15 = 2/3
AS = 15 (2/3)
AS = 5 (2)
AS = 10

3.
AB = 5
AD = 2
DE = 4

BC : DE = AB : AD
BC/DE = AB/AD
BC/4 = 5/2
BC = 4 (5/2)
BC = 2 (5)
BC = 10

4.
AB = 6
AD = 2
BC = 9

DE : BC = AD : AB
DE/BC = AD/AB
DE/9 = 2/6
DE = 9 (2/6)
DE = 9 (1/3)
DE = 3

semoga membantu
mohon dikoreksi bila ada kesalahan