How is unit rate related to the linear equation?

https://www.khanacademy.org/math/cc-eighth-grade-math/cc-8th-linear-equations-functions/cc-8th-graphing-prop-rel/v/graphing-proportional-relationships-example

Step-by-step explanation:

A proportional relationship between two quantities is one in which the two quantities vary directly with one and other. If one item is doubled, the other, related item is also doubled. Because of this, it is also called a direct variation. The equations of such relationships are always in the form y = mx , and when graphed produce a line that passes through the origin. In this equation, m is the slope of the line, and it is also called the unit rate, the rate of change, or the constant of proportionality of the function.

answer:   28.56 feet (approx)

step-by-step explanation:

since, triangle abc has measure of angle c equal to 55 degrees, measure of angle abc equal to 90 degrees, and length of bc equal to 20 feet.

we have to find out the measurement of segment ab.

therefore, tan 55° =

but bc = 20 feet.

⇒ tan 55 ° =  

⇒ ab = 20 × tan 55 °

⇒ ab = 20 × 1.42814800674

⇒ ab = 28.5629601348   ≈ 28.56 feet