I'm having trouble with these SAT prep practice questions and was hoping for some help.
1) How do you know that a scalene triangle can never be and isosceles triangle?
2) How do you know that a right triangle can never be an equilateral triangle?
3) Must every right angle also be a scalene triangle? Why or why not?
4) What is the difference between an altitude and a median of a triangle?
5) Can a altitude and a median ever be the same segment? Justify you answer.
6) Which is longer, the hypotenuse of a right triangle or the sum of the length of the two legs? Justify your answer.

Question

I'm having trouble with these SAT prep practice questions and was hoping for some help. 
1) How do you know that a scalene triangle can never be and isosceles triangle?
2) How do you know that a right triangle can never be an equilateral triangle?
3) Must every right angle also be a scalene triangle? Why or why not?
4) What is the difference between an altitude and a median of a triangle?
5) Can a altitude and a median ever be the same segment? Justify you answer.
6) Which is longer, the hypotenuse of a right triangle or the sum of the length of the two legs? Justify your answer.