Hi there! Look at the attachments along with my explanation. Before we are going to answer your problem, we need to know the basic Trigonometric Ratio first.
Now see my attachments. The first attachment is the original image from your problem.
The second attachment is when we draw to focus on angle H (in a better perspective)
The third attachment is when we draw to focus on angle G in a better perspective.
Now that we know tanA = opposite/adjacent
Define A = any angles.
Therefore,
tanH = 1/2
tanG = 2/1 = 2
Answer