Answer:
137 degrees
Explanation:
in the triangle with 60 degrees : the top angle must be also 45 degrees (the same as the angle above it).
then its third angle must be 180 - 60 - 45 = 75 degrees (because the sum of all angles is always 180 degrees in any triangle).
then the sum of this 75 degrees angle, then the neighboring 68 degree angle and the next one (the left angle in the triangle with 100 degrees) together must be again 180 degrees, because all angles around a point on one side of a line are 180 degrees (a half circle).
that means this left angle of the 100 degrees triangle is
180 - 75 - 68 = 37 degrees.
that means that the right angle of the 100 degrees triangle is
180 - 37 - 100 = 43 degrees (again, because of the sum in a triangle).
and now that gives us the ? angle as
180 - 43 = 137 degrees
because this is again the sum around s point on a line (the line is the arrow line starting at the 100 degrees angle pointing leading and pointing to the bottom right).