ANSWER
The correct answer is D

EXPLANATION
We need to use the distance formula to determine the length of all sides and then add them up.
The distance formula is given by,

Firs let us find the distance between (7, 1) and (-6, 1).

This implies that,



Next, we find the distance between (7,1) and (10,6)




Next we find the distance between (-6,1) and (10,6)




We now add all the distance to get,

This implies that,

to the nearest tenth