No. An equilateral polygon with 5 or with 7 or more sides will not tessellate a plane.
yes
No, a hexagon is not a tessellation. Some hexagons can tessellate a plane, others will not.
Yes
ANY AND EVERY plane triangle totals 180o. Spherical triangles are far too complicated for this site.
No.
Yes
No
No, it will not tessellate.
yes
heptagon and an equilateral triangle
Well gosh, every square is equilateral.
No.