Each sandbox will need 4,200 lbs of sand. 42,000/10=4,200
One temperature colder that -7.2 F would be -9 F.
-9 < -7.2
The -9 would be 1.8 units to the left of -7.2 on the number line.
Number 4 is the third one, letter H I believe
Are there any dimensions on the triangle? or is it in terms of s? if so the answer would be 2s/sqrt(3) or you can rationalize the bottom and youd get 2sqrt(3)s/3