7/4 is the answer to your question
Step-by-step explanation:
wow, how complicated can one phrase this ...
the point being :
1 ft = 12 in and vice versa (1 in = 1/12 ft)
so, any measurements given in feet but needed in inches need to be multiplied by 12.
and any measurements given in inches but needed in feet need to be divided by 12.
so,
3.5 ft = 3.5×12 = 7/2 × 12 = 7×6 = 42 in
27 in = 27/12 = 9/4 = 2 1/4 or 2.25 ft
The ratio is 37:15
For every 37 fiction books there are 15 non fiction books
37/15. = 2 7/15
ANSWER

EXPLANATION
We need to use the Pythagoras Theorem to find the height of the triangle.





Take positive square root to get;

Area =½bh

