Number of combinations of 5 women from 7 = 7C5 = 7*6 / 2 = 21
for men its 7C4 = 7*6*5 / 3*2 = 35
Total number of ways = 21*35 = 735
the second one, and the third one
Think about the fact that you can have two types of isosceles triangle: one of them that is a right triangle (isosceles right triangle) such as a 45-45-90 triangle and the other type can be just a regular triangle that has two sides that are congruent but it isn't a right triangle.
Thus, you would need more info about the triangles in order to conclude that the two isosceles triangles are congruent to each other.
