geometry problems

Geometry problems (30..39)

		problems 21..29
		problems 40..49

30.

Calculate angle x:

31.

Calculate x in the picture below:

32.

In picture below AB=BC=CA=CD=AE.
Prove that BC=3.AF

33.

Calculate the area of rectangle ABCD if BD=10.

34.

Given is square ABCD with some angles.
Calculate LAEF.

35.

Calculate angle x in picture below.

36.

Prove that r² = ab

37.

Calculate the length of x in picture below.

38.

ABCD is a rectangle.
AB=4, AD=3.
E is a random point on CD.
Calculate the area of triangle EFG.

39.
The triangles other than ΔABC are equilateral.
LA = 60 degrees.
Prove that area S + S₂ = S₁ + S₃.