must a function that is decreasing over a given interval always be negative over the same interval? explain?

470 feet

Step-by-step explanation:

Given that,

Three adjacent lots had road frontage measured to be 200.1 ​ft, 135.45 ​ft, and 55.133 ft.

We need to find the total length of the frontages of these three​ lots. It can be simply calculated by adding these three lengths ie.

Total length = 200.1 ​ft + 135.45 ​ft + 55.133 ft

= 471 feet

or

= 470 feet

So, the total length of these three lots is equal to 470 feet.