Grade 11
Problem of the area in the tunnel's entry
A wall painter needs buy inks for painting the striped area in the below figure, which represents the entry in a tunnel with semicircular design. As he doesn't know trigonometry, he wants your aid to achieve this area, for buying the certain quantity of ink. Teacher Cacildo Marques decided contribute and, for this, ofers a prize to the first who will send a solution.
