Is angle $EBA$ is a right angle?

Question

I am having trouble analyzing this image to identify the statement as true or false:

The statements are:

1. angle $EBA$ is a right angle. - I think it's false, but I can't think of a theorem or postulate that will justify my answer.

2. $\overleftrightarrow{FG}$ is perpendicular to plane $H$. - I think this is wrong because $\overleftrightarrow{FG}\subseteq{H}$

please help. thank you

Answer 1

I think there are two mutually perpendicular planes intersecting along ABC in the 3D figure I have redrawn. It is assumed ABC is perpen to the bigger plane on which the union is mounted.From the picture assuming BE is is parallel to the plane shown and ABC is perpendicular to it..then

it is correct EBA is a right triangle.

FG is perpendicular to plane K, the piercing point is C.