Please answer this big question nobody ever answers my questions im sad :(

Step-by-step explanation:

1.

3,4,5 will make a triangle.

2.

sum of any sides > third side

difference of any two sides < third side

3+4=7>5

4+5=9>3

5+3=8>4

again

4-3=1<5

5-3=2<4

5-4=1<3

so it makes one triangle.

3.

3,4,8

4.

3+4=7 not >7

again

8-4 =4 not <3

so they do not make a triangle.

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'.