meh wish this forum had asy.
Let the intersection point of AE and GE be X, and let the intersection point of AE and GM be Y.
(XY+EM)*EM/2=80, (XY+10)*10/2=80, XY=6
Let the foot of perpendicular of G to AE be Z.
proportion - triangle GXY and triangle GEM
GZ : 6 = (GZ+10) : 10, 6GZ+60=10GZ, GZ=15.
therefore, altitude to EM in GEM is 10+15=25.
answer : 25