The answer for number 4: Temperature is an average of average heat. Heat is the average kinetic energy and thermal energy is kinetic energy.
(I can't see the answer for number 10... it would be good if you told me the question)
No, it never can be a right triangle.
First, all the angles of an equilateral triangle is 60 degrees because all angles are the same and all the angles add up to 180:
180/3 = 60.
So if it is a right angle it needs one angle 90 degrees which an equilateral triangle can't have,
I think my answer is a because it can’t be B and it can’t be C and it can’t be D so my answer is a