How to tell if a triangle is acute obtuse or right using pythagorean theorem?

Which of the binomials below is a factor of this exression? 16x^2+40xy+25y^2 a.4x-5y b. 2x-5y c.4x+5y d.2x+5y

Which line is parallel to the line that passes through the points (2, –5) and (–4, 1) a. y=-x+5 b. y=-2/3x+3 c. y=2/3x-2 d. y=x+5

I'm a polygon i have no parallel lines i am formed 3 line segments i have one right angle two of my angles are angles what am i