Question

The shape of frustum of a cone of height 21 cm. The radii of its two circular ends are 3 cm and 2 cm. Find the capacity of the glass and curved surface area of frustum.

Answer 1

above it is solved... hope it helps you...

Answer 2

The capacity of the glass and curved surface area of frustum are 418 cm³ and 330.31 cm²

Step-by-step explanation:

• Given data

        Height of frustum cone (H) = 21 cm

        Smaller radius frustum cone (r) = 2 cm

        larger radius frustum cone (R) = 3 cm

        $\mathbf{Where(\pi) =\frac{22}{7}}$

• Then slant height (L) of frustum cone are given by formula

        $\mathbf{L =\sqrt{H^{2}+(R-r)^{2}}}$

        $\mathbf{L =\sqrt{21^{2}+(3-2)^{2}}}$

        $\mathbf{L =\sqrt{442}}$   cm

        L = 21.02 cm

• Now curved surface area of frustum cone are given by formula

        $\mathbf{C.S.A =\pi \times L\times (R+r)}$    

        $\mathbf{C.S.A =\frac{22}{7} \times 21.02\times (3+2)}$

        On solving, we get

        $\mathbf{C.S.A =330.31 \ cm^{2}}$ = This will be curved surface area of frustum.

• Now volume or capacity of frustum cone are given by formula

        $\mathbf{Capacity (V)=\frac{1}{3}\times \pi \times H\times (R^{2}+r^{2}+Rr)}$

        $\mathbf{Capacity (V)=\frac{1}{3}\times \frac{22}{7} \times 21\times (3^{2}+2^{2}+3\times 2)}$

        On solving, we get

        $\mathbf{Capacity (V)=418 \ cm^{3}}$= This will be capacity of frustum.