10 1/2 ft=2x-18 in
convert ft to in--10 1/2ft=126 in
126=2x-18
2x=144
x=<em>72 inches or 6 feet</em>
All three sides always add up to 360 so add the given measures and subtract it from 360 and that would give you your answer.
I think the answer is 78 because more usually mean addition so 57+21=78
Add 0.1 to 0.0(54) to get 0.1(54).
A=10ft because A is 8ft so round that to the nearest ten your answer is 10ft
