Answer:
[tex]\large\boxed{7.\ L.A.\approx7771.5\ mm^2}\\\\\boxed{8.\ L.A.\approx621.7\ in^2}\\\\\boxed{9.\ L.A.\approx628\ m^2}[/tex]
Step-by-step explanation:
The formula of a lateral surface of a cone:
[tex]L.S.=\pi rs[/tex]
r - radius
s - slant height
====================================
[tex]\pi\approx3.14[/tex]
[tex]7.\\r=45mm,\ s=55mm\\\\L.A.=\pi(45)(55)=2475\pi\ mm^2\\\\L.A.\approx2475\cdot3.14=7771.5\ mm^3[/tex]
[tex]8.\\r=11\ in,\ s=18\in\\\\L.A.=\pi(11)(18)=198\pi\ in^2\\\\L.A.\approx198\cdot3.14=621.72\ in^2\approx621.7\ in^2[/tex]
[tex]9.\\r=10m,\ s=20m\\\\L.A.=\pi(10)(20)=200\pi\ m^2\\\\L.A.\approx200\cdot3.14=628\ in^2[/tex]
