teman tan bantu saya dong.. sama caranya ya..

29) BC = 10/ cos 30
= 10/ ½√3
= 20/3 √3

30) OF = garis dr titik F ke garis AC
OB = ½ s√2
= ½.12 √2
= 6√2

BF = 12

OF = √OB²+BF²
= √(6√2)²+12²
= √36.2 + 144
= √36(2+4)
= 6√6

31) BP = √1²+½²
= √1+¼
= √5/4
= ½√5

PG = ½
BG = √2

Cos PBG = BP²+BG²-PG² / 2.BP.BG
= (5/4 +2- ¼) / (2.½√5.√2)
= 3 /√10

Sin PBG = ¹/10 √10