Which statement is true about perpendicular lines?

Help please!!

What is the length of the missing leg in this right triangle? 18 mm 24 mm 26 mm 32 mm

Which of the following transformations will always produce a congruent figure?

Mr. jones determined that the equation y = 98 - 16/5 x could be used to predict his students' unit test scores, based on the number of days, x, a student was absent during the unit. what was the meaning of the y-intercept of the function? (by the way the 16/5 is a )