✔ 最佳答案
First, you should know angle DBC=45 (angles on a st. line),
angle EDB=70 (sum of interior angles of a 4-sided polygon=360),
angle DCB=45 (sum of interior angles of a triangle=180),
and, length BD=21m, (property of isosceles triangle)
Then, you have to do the followings:
1) Construct a point, say F, which is perpendicular from B to the line DE.
2) Draw a line connecting B and F.
3) Draw another line from B to E.
Find length of BF.
BF=21*sin(70)=19.734m
Find length of BE.
BE=sqrt(EF^2 + BF^2)
BE=sqrt(38^2 + 19.734^2)
BE=42.818m
Find angle BEF and angle AEB.
cos(angle BEF)=EF/BE=38/42.818
angle BEF=27.443
angle AEB=65-27.443=37.557
Find AB and AE.
sin(angle AEB)=AB/BE
AB=42.818m*sin(37.557)=26.100m
cos(angle AEB)=AE/BE
AE=42.818m*cos(37.557)=33.944m