Diện tích của tam giác đó là:

\(\left(\dfrac{5}{3}\times\dfrac{3}{2}\right)\div2=\dfrac{15}{12}=\dfrac{5}{4}\)

\(S=7+\dfrac{7}{3}+\dfrac{7}{6}+\dfrac{7}{10}+\dfrac{7}{15}+\dfrac{7}{21}+\dfrac{7}{28}+\dfrac{7}{36}+\dfrac{7}{45}+\dfrac{7}{55}\\ =7+\left(\dfrac{7}{3}+\dfrac{7}{21}\right)+\left(\dfrac{7}{6}+\dfrac{7}{36}\right)+\left(\dfrac{7}{15}+\dfrac{7}{45}\right)+\dfrac{7}{10}+\dfrac{7}{28}+\dfrac{7}{55}\\ =7+\dfrac{8}{3}+\dfrac{49}{36}+\dfrac{28}{45}+\dfrac{7}{10}+\dfrac{7}{28}+\dfrac{7}{55}\\ =7+\left(\dfrac{8}{3}+\dfrac{49}{36}+\dfrac{28}{45}\right)+\dfrac{7}{10}+\dfrac{7}{28}+\dfrac{7}{55}\\ =7+\dfrac{93}{20}+\dfrac{7}{10}+\dfrac{7}{28}+\dfrac{7}{55}\\ =7+\left(\dfrac{93}{20}+\dfrac{7}{10}\right)+\dfrac{7}{28}+\dfrac{7}{55}\\ =7+\dfrac{107}{20}+\dfrac{7}{28}+\dfrac{7}{55}\\ =\dfrac{140}{11}\)