Printing value of volume and surface area
echo ( " Volume ▁ Of ▁ Frustum ▁ of ▁ Cone ▁ : ▁ " ) ; echo ( volume ( $ small_radius , $ big_radius , $ height ) ) ; echo ( " STRNEWLINE " ) ; echo ( " Curved ▁ Surface ▁ Area ▁ Of ▁ Frustum ▁ of ▁ Cone ▁ : ▁ " ) ; echo ( curved_surface_area ( $ small_radius , $ big_radius , $ slant_height ) ) ; echo ( " STRNEWLINE " ) ; echo ( " Total ▁ Surface ▁ Area ▁ Of ▁ Frustum ▁ of ▁ Cone ▁ : ▁ " ) ; echo ( total_surface_area ( $ small_radius , $ big_radius , $ slant_height , $ height ) ) ; ? >