I'm not sure which image you have a question on, so I'll just solve both.
Top Image:
We know that the sum of the angles will add up to 180 and that the angles of the triangle are f, f, and 68°. Therefore, we can set up the following equation:
f + f + 68° = 180°
Solving this gets f = 56°
Bottom Image:
We know that the sum of the angles will add up to 180 and that the angles of the triangle are 23°, 23°, and g. Therefore, we can set up the following equation:
you have to add all of the together so like graph number 1 add all those numbers together and then divide by how much numbers there are and that is the median