Try these solutions:
Task 1.
a) the required angle is arctan(CG/AC);
b) according to the condition CG=AE=11.4 (cm.);
c) BC=EH=9.6 (cm.), then
[tex]AC=\sqrt{AB^2+BC^2}=\sqrt{18.4^2+9.6^2}=\sqrt{430.72} (cm.);[/tex]
d) the required angle is:
[tex]arctan\frac{CG}{AC}=arctan\frac{11.4}{\sqrt{430.72}}=arctan(0.549297)=28.5=29[/tex]
Answer: 29°
Task 2.
a) the required angle is EFV (see the attached picture): arctan(EV/FE);
b) to calculate FE: FE=0.5AB=7.25 (cm.);
c) to calculate EV:
[tex]EV=\sqrt{DV^2-DE^2} =\sqrt{17.2^2-(14.5/\sqrt{2})^2}=13.80996 (cm.);[/tex]
d) to calculate the required angle:
m(∠EFV)=arctan(13.80996/7.25)=arctan(1.9048)≈62.302°=62°.
Answer: 62°
