ABC is an isosceles triangle with sides AB = AC = 17 cm and BC = 30 cm. AD is a median to base BC. Then the length of AD is
1
6 cm
2
8 cm
3
9 cm
4
12 cm
ABC is an isosceles triangle with sides AB = AC = 17 cm and BC = 30 cm. AD is a median to base BC. Then the length of AD is