The area of kite when both diagonals are given is
[tex]A=\frac{d_{}\times D}{2}[/tex]where d=17 m and D=21 m. By substituting the given values, we get
[tex]\begin{gathered} A=\frac{17\times21}{2} \\ A=178.5 \end{gathered}[/tex]then, the answer is 178.5 square meters