Answer:
9 sides
Explanation:
Formula for finding interior angles of all polygons : 180 ( n - 2) / n = A
(n being the amount of sides it has)
This information is important so you can plug in the numbers that you already know
We know that the interior angle measures to 140 degrees
180 (n - 2) / n = 140
multiply both sides by "n"
(n - 2) x 180 = 140n
Distribute 180 to what's inside the parenthesis
180n - 360 = 140n
Subtract 140n and add 360 to each side (which just moves 360 to the other side of the "="
40n = 360
Divide 40 by both sides
n = 9
hope this helps :)