Question

find the perimeter ,area and the length of diagonal of a rectangle having​

Answer 1

$let \: the \: lenght \: and \: breadth \: be \: l \: and \: b \\ perimeter(p) = 2(l + b) \\ area(a) = l \times b \\ diagonal (d)= \sqrt{ {l}^{2} + {b}^{2} } \\ equation \: that \: contains \: the \: allthing \\ \frac{ {p}^{2} }{4} = {d}^{2} + 2a$