Because it is a 90° angle and the legs are congruent, the legs intersect with the hypotenuse at the same angle, so the other, unnamed angle at the bottom left is equal to x.
Now we can state that:
2x + 90 = 180
2x = 90
x = 45
It would be a a 6 by 5 inch rectangle, since the height is 6in and the width is 5in. Those are what would make up the cross section.
So, the right option is 1. so if my ans was helpful u can follow me.
The answer would be -10/20 which is simplified to -1/2