Tolnggg dii jw beserta cara penyelesainnya yaaa...

a) bc² = ab² + ac²
bc² = 9² + 12²
bc² = 81 + 144
bc² = 225
bc = √225
bc = 15
2) bd/ab = ab/bc
bd/9 = 9/15
bd = 9×9/15
bd = 81/15 = 5,4
3) ad/ab = ac/bc
ad/9 = 12/15
ad = 12×9/15
ad = 7,2