Answer: width is 7
Step-by-step explanation:
Formula V=L×W×H
.. 7812= 36×W×31
7812=1116W
Divide by 1116
7=W
one interior angle = 30° <==== this one is given
second interior angle = 180 - 40 = 140° <=== interior angle + exterior angle = 180
third interior angle = 180 - 30 - 140 = 10° <=== angles in a triangle = 180