If m ACD = 30 => m DCB = 60.
In triangle ACD:



AC^{2}+CB^{2}=AB^{2} => AB=

=32.
=> P=16+32+

=48 +

.
2400 because it is only 93 away from 2493 and 2353 is more than 93 away
The answer is c. we add 4x^4+x^4. then cancel the -x^2+x^2 and also the -x and x . so, we are left with the -1. that's why the answer is c