Answer:
B
Step-by-step explanation:
Ok so what you're trying to do is get L by itself so to do this you move everything to the other side:
A=L*WH

=L
So you answer would be:
C
Answer:
8:9
Step-by-step explanation:
ratio of areas = (ratio of sides)²
64/81 = (ratio of sides)²
Square root both sides
8/9 = ratio of sides