Answer:
A. 12.5 ft
B. not in proportion (should be 2.5 ft, not 2.25 ft)
Step-by-step explanation:
A scale model is one in which all linear dimensions of the model have the same ratio to corresponding linear dimensions of the object being modeled.
Here, that relationship means ...
actual length/model length = actual height/model height
actual length/(1.25 ft) = (10 ft)/(1 ft)
actual length = (1.25 ft)(10/1) = 12.5 ft
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If the actual wheel has the same scale, we will have ...
actual diameter/(6 inches) = (10 ft)/(1 ft)
actual diameter = (6 inches)(10/1) = 60 inches = 5 ft
actual radius = (5 ft)/2 = 2.5 ft . . . . . at the same model scale
Since the actual wheel radius is 2.25 feet, it is not in proportion to the rest of the model.