Frasaingeachd triantain 1 \(A = \frac{1}{2}bh\)

\(= \frac{1}{2} \times 2 \times 7\)

\(= \frac{1}{2} \times 14\)

\(= 7\,c{m^2}\)

Farsaingeachd ceart-chearnaich 2 \(A = l \times b\)

\(= 5 \times 7\)

\(= 35\,{cm^2}\)

Frasaingeachd triantain 3 \(A = \frac{1}{2}bh\)

\(= \frac{1}{2} \times 9 \times 7\)

\(= \frac{1}{2} \times 63\)

\(= 31.5\,c{m^2}\)

\(Farsaingeachd\,iomlan = 7 + 35 + 31.5 = 73.5\,c{m^2}\)