Here's the solution,
Area of Square pyramid = Areas of triangles + Area of square base
and we know, the triangles have equal base and same height, so their areas will be equal
Area of each triangle :
=》
[tex] \dfrac{1}{2} \times 9 \times 7[/tex]
=》
[tex] \dfrac{63}{2} [/tex]
=》
[tex]31.5[/tex]
So, are of triangle = 31.5 ft²
since, there are four triangles ,
Area = 31.5 × 4
=》126 ft²
Area of square base = 9 × 9 = 81 ft²
Hence, Area of pyramid = 81 ft² + 126 ft²
=》207 ft²