7th grade math help please and thank you

Me! #1 write an equation for the interior angles of this triangle that uses the triangle sum theorem. #2 what is the value of x? #3 what is the measure of #4 classify the triangle above as acute, obtuse, or right. state your reason in a complete sentence.

Solve for x and select the correct answer

Solve for x where 0 equation: cot^2x+2cotx+1=0