panjang AC dan HC berturut turut adalah

ac/eh = ab/ef
ac/25 = 20/50
ac = 20×25/50
= 10

x/x+12 = ab/ef
x/x+12 = 20/50
x×50 = (x+12) 20
50x = 20x+240
50x-20x = 240
30x = 240
x = 240/3
x = 80

HC = x+12
= 80+12
= 92

Semoga membantu:)