A right triangle has vertices (−7,9),(3,9),(−7,−15). Find the perimeter of the triangle. please help. a simple formula will due. and an explanation

  60

Step-by-step explanation:

If the sides of the triangle have lengths a, b, c, the perimeter is their sum:

  P = a + b + c

Any of the side lengths can be found using the distance formula. However, since two of the sides are aligned with the axes, their lengths are easily found by subtracting coordinates.

If the points are labeled A, B, C, in order, then the two right-angle sides are ...

  c = AB = 3 -(-7) = 10

  b = AC = 9 -(-15) = 24

The Pythagorean theorem tells you that you can find the third side from the relation ...

  a² = b² +c²

  a² = 10² +24² = 676

  a = √676 = 26

Now, we can use these values in the formula for the perimeter:

  P = a + b + c = 26 + 24 + 10

  P = 60

The perimeter of the triangle is 60 units.

for the friend request.

when a figure, such as triangle (xyz) is reflected over the line y = x to create x'y'z' the x-coordinates and y-coordinates of the original image (pre-image) will be reversed for the image. (e.g., (x, y) > (y, x)) this means that the pre-image position of the x- and y-coordinates switch places which in turn provides a mirror like image of the original xyz.  

i notice that when i draw a line segment from x to x', that the points are parallel from each other -- they are exactly across from each other and do not intersect with any other points.  

yes, think i would see the same characteristic if you drew the line segment connecting y with the reflecting line and then y' with the reflecting line because of the essence of reflections. because it is a mirror image, each point was effected the same way which leads me to conclude that they same would apply to y and y'.