Question

The cross section of a Canal in the form of trapezium in it if the top of canal is 15 M wide the bottom is 8 M and the area of cross section is 138 main square find its depth

Answer 1

$let \: \: a = 15 \: \: \: \: and \: \: b = 8 \\ let \: \: height \: \: be \: \: h \\ then \: \: area = \frac{1}{2} h(a + b) \\ h = \frac{2 \times area}{a + b} = \frac{2 \times138 }{15 + 8} = 12 \: m$