Question

find the lateral area and surface area of a right cone with radius 6 in. and height 8 in. give your answers in terms of pie

Answer 1

$r=6in\\\\H=8in\\\\A=\pi rl\\\\Pythagoras\ theorem:\\\\r^2+H^2=l^2\\\\l^2=6^2+8^2\\\\l^2=36+64\\\\l^2=100\\\\l=\sqrt{100}\\\\l=10\ (in)$

$A=\pi\cdot6\cdot10=60\pi\ (in^2)$