We start by reviewing the method for calculating the length of a straight line segment.
a. Find the length of the straight line segment from $(1,2)$ to $(5,4)$, shown in Figure 2. The lengths of the two sides of the right triangle are $4-2=2$ and $5-1=4$. You can use the Pythagorean Theorem to determine the length of the hypotenuse.
b. Now generalize this example to find a formula for the length of the segment of the straight line $y=m x+c$ from $x=a$ to $x=b$. This is the line segment connecting the points ( $a$, $\qquad$ ) and (b, $\qquad$ ). Show the necessary work to get the length equal to $(b-a) \sqrt{1+m^2}$. Check your answer to part a using this formula.
c. Write an expression for the length of the curve in Figure 3 made up of four straight line segments with slopes $m_1, m_2, m_3$ and $m_4$.