Which pair of lines are perpendicular lines?

#12 find the value of x. #13 find the value of the variable.

Which statement is true 1.the pythagorean theorem can be used to find the missing side of any triangle 2.the pythagorean theorem can be used to find the missing side of any polygon 3. the pythagorean theorem can be used to find the missing side of any right triangle 4.the pythagorean theorem can be used to find the missing side of any isosceles triangle

How to choose the sign of the radical in the denominator of the formula for the distance from a point to a line.