By definition, the standard form of a polynomial is given by:

We then have the following polynomial:

Rewriting in its standard form we have:

We realize that the polynomial has three terms, therefore, it is a trinomial.
The largest exponent of the polynomial is three and therefore we have a trinomial of degree three.
Answer:

Three degree trinomial.
1) 2x+1x= 63
2) 3x= 63
3) 3x/3= 63/3
4) x= 21
5) 2(21)+1(21)=63
6) 42+21= 63
The 2 groups would be 42 to 21.
A = l²
A = 7.2²
A = 51.84
51.84 inches