radius: 21 cm
V= 9702 cm³
1) We know the Base area of a cone is 1,386 u². We know the base of a cone is a circle.
[tex]\begin{gathered} A=\pi r^2 \\ \\ 1,386=\frac{22}{7}r^2 \\ \\ \frac{22}{7}r^2=1386 \\ \\ 7\cdot \frac{22}{7}r^2=1386\cdot \:7 \\ \\ 22r^2=9702 \\ \\ \frac{22r^2}{22}=\frac{9702}{22} \\ \\ r^2=441 \\ r=21 \end{gathered}[/tex]
Note that we have used the given approximation to pi.
2) Now, for the volume, we can write the following notice that r=h
[tex]\begin{gathered} V=\frac{1}{3}\pi r^2h \\ \\ V=\frac{1}{3}(\frac{22}{7})(21)^2(21) \\ \\ V=9702\:cm^3 \end{gathered}[/tex]
