area ABEC
\(s = \frac{25 + 26 + 17}{2} = 34\)
area ΔBEC \(= \sqrt{34 \times 9 \times 8 \times 17}\)
\(= 17 \times 3 \times 2\times 2\)
\(= 204 cm^2\)
area ΔBEC \(= \frac 12 \times 17 \times h = 204\)
\(h = \frac{204 \times2}{17} = 24\)
area trap. ABCD \(= \frac 12(60 + 77) \times 24\)
\(= 137 \times 12\)
\(= 1644 cm^2\)