Given that,
The radius of the open side, r₁ = 10 cm
The radius of the upper base, r₂ = 4 cm
Slant height, l = 15 cm
To find,
The area of material used for making it.
Solution,
The area of material used for making it = CSA of the frustrum + Area of the circle portion of upper side
[tex]A=\pi (r_1+r_2)l+\pi r_2^2\\\\A=\pi (10+4)\times 15+\pi \times 4^2\\\\A=709.99\ cm^2[/tex]
So, [tex]709.99\ cm^2[/tex] of the area of material is used for making it.