Question

What is the value of x in this heptagon?

Answer 1

The sum of the angles in a heptagon is 900 degrees

so add them
113+168+129+101+x+144+122=900
777+x=900
minus 777 from both sides
x=123

x=123 degrees

Answer 2

I think you need to add all the numbers 
hope this helps 
but i 'm not sure