Question

Does anyone know this?

Answer 1

Use this formula to get the total angle measurement of the figure:

T=180(n-2)

Since there are 7 sides, the total measurement must be:

180(7-2)

180(5)

900 degrees

Set up an equation and solve for x:

123+121+127+128+139+125+x=900

763+x=900

x=137

So the missing angle is 137 degrees.

Hope this helped!

Answer 2

Basically add the rest of the numbers and take away by 1260

180 times7