we know that
The <u>Triangle Inequality Theorem</u> states that the sum of any 2 sides of a triangle must be greater than the measure of the third side
so
Let
s------> the length of the third side

therefore
<u>The answer part a) is</u>

we know that
the perimeter of a triangle is the sum of the length sides
In this problem

<u>For
</u>
the perimeter is equal to

<u>For
</u>
the perimeter is equal to

so

therefore
<u>the answer part b) is</u>

That's impossible to say. The radius of a square is meaningless.
Practically anything above -8
Such as -7, 2, 15600, anything not under -7.9