Please help me with this question

a=50 degrees

Step-by-step explanation:

Look at the triangle in the middle. You can find two missing angles to calculate the third one.

50 and 130 are supplementary, so 50 must be the upper right angle. The angle opposite to 80 has to be equal to it, of the upper left angle is 80.

A triangle is 180 degrees total, and 180-(50+80)= 50.

The missing angle for the triangle is 50, and since "a" is opposite to it, the values are equal.

a=50 degrees