Determine the rms and average value of the wave-form show in fig.

The slope of the curve AB= BC/AC = 20/T. Next consider the function $y$ at any time $t$.It is seen that 

DE/AE= BC/AC =10/T

or       $$\begin{gathered} (y-10)t=10/T \\ y=10+(10/T)t \end{gathered}$$

This gives us the equation for the function of one cycle 

or rms value value =$10\sqrt{7/3}$=15.2