Perfect square is
a²+2ab+b²
so just take the square root of the end ones and add then double to get middle term
A.
m+10=10m, doubled is 20m
nope
B.
m+5=5m, doubled is 10m, yep
C.
m+2√15=fancy thing that won't get to 36m
D.
m+12=12m, doubled is 24m, yep
B and D
If you add the two numbers, 10 +8 is 18. The fractional parts are 1/4 and 2/4 which equals 3/4. So the total length is 18 and 3/4 feet.
You could do 228/6 = 38
2280/60 = 38
hope this helps you
