1. Decagon ABCDEFGHIJ is rotated centered at G by an angle of x, and moves point D to J. If x<180, find x.
2. Let G be the center of equilateral triangle XYZ. A dilation centered at G with scale factor -2/3 is applied to triangle XYZ to obtain triangle X'Y'Z'. Let A be the area of the region that is contained in both triangles XYZ and X'Y'Z'. Find A/the area of XYZ.
3. Let T be a point inside square EFGH such that TE=1, TF=2, and TG=3. Find angle ETF.
1. Angle x = 65 degrees.
2. The ratio is (2/3)^2 + (2/3)^3 = 20/27.