Need help on this please

Type the correct answer in the box. use numerals instead of words. if necessary, use / for the fraction bar. the length of each side of a square increases by 2.5 inches to form a new square with a perimeter of 70 inches. the length of each side of the original square was inches.

Used for an event that has been completed before the present moment in time. simple past past perfect perfect progressive past perfect progressive

What is the source of tension in this excerpt? ellery searching everything insects filling the light fixtures ellery standing on the desks louise carpenter whispering