Classify this triangle by its sides.

hello from mrbilldoesmath!

answer:

x - 3

discussion:

x^2 - 9 = (x-3) (x+3)   so

(x^2-9)/ (x + 3) = x-3

you,

mrb

i hope this is what you were looking for.

see attached graph

your question is incomplete, write all the numbers in the sequence that it tells you.  

step-by-step explanation:

it would open into a square depending on the type of envelope i’m not sure about the second part