tolong....................

Kongruen dan kesebangunan

15.
Δ ABC  kongruen  dgn Δ PQR
AC = PR 
2x -2 = 2
2x = 4
x = 2

PQ =  AB
PQ = 3x - 2
PQ= 3(2) - 2
PQ = 6-2
PQ = 4 cm

16.

EF =  (CD x AE + AB x DE) / ( AE + DE)
EF = (6 x 5  + 18x 3) / (5 +3)
EF = (30 + 54) /(8)
EF = 84/8
EF = 10,5  cm