Select whether the following statement is always true, sometimes true, or never true. in the plan of a proof, you should use the plan that was used on previous theorems.
always
sometimes
mever are the choices

This statement is sometimes true.

Step-by-step explanation:

In the plan of a proof, you should Sometimes use the plan that was used on previous theorems.

We can sometimes take in consideration, the previous plans in theorems and proofs to derive new one. If we always keep using the plan that was used in previous theorems, then new things cannot be invented.

5

step-by-step explanation:

false

step-by-step explanation:

the reason i say this is because for a certain length of sides you can pick any two and the length is wither equal or greater than the third side and in this case it's not.

3 + 5 = 8

8 is smaller than 9 which is the third side.

hope this : )