Alternate angles explain

What is the slope of a line that is perpendicular to y = 3x + 1

What is the average rate of change for this function for the interval from x=2 to x=4 ?

The perimeter of an equilateral triangle is 4 cm more than the perimeter of a square and the length of a side of the triangle is 8 cm more than the length of a side of the aware. find the length of a side of the equilateral triangle