My challenge was on trying to determine the angles: My approach;
came up with a number of equations: ie
##m+n=70^0##
##r=p+40^0##
##q-2r=100^0, ⇒ r=50^0 + \dfrac{1}{2} q##
then it follows that,
##2q+100^0=180^0##
##⇒q=40^0, r=70^0, p=m=30^0, n=40^0##
##m+40^0+t=180^0, ⇒t=110^0##
and...