Two lines have equations y + m1x + c1 and y + m2x +c2, m1m2 = -1. prove that the lines are perpendicular.

Can (3,5 and square root 34) be sides on a right triangle?

The midpoints of the sides of the large square are joined to form a smaller square. what is the area of the smaller square

When you have 25 numbers, and jake picks 3 random numbers and puts them back, what is the chance bob has of picking those 3 numbers when he picks 6 random numbers (without putting them back)? explain.