27) panjang CD = 28) pnjng BC = 29) panjang TU=

27)
AB² = BD x BC
6² = 4 x BC
36 = 4 x BC
BC = 36 : 4
BC = 9 cm
maka,
CD = BC - BD = 9 - 4 = 5 cm ... (a)


28)
EF = AB = 18 cm
BD = EF-DE = 18-12 = 6 cm
maka,
BC/EF = BD/DE
BC/18 = 6/12
12xBC = 6x18
12xBC = 108
BC = 108:12
BC = 9 cm ... (b)


29)
TU
= ((TSxPQ)+(PTxSR)) : (PT+TS)
= ((2x15)+(5x22)) : (2+5)
= (30+110) : 7
= 140/7
= 20 cm ... (d)