Calculate the length, $l$, of the slant height of the cone.

Calculate the area that is painted red.

$\sqrt {{5^2} + {{12}^2}}$     (M1)

Note: Award (M1) for correct substitution in Pythagoras Formula.

=$13{\text{ (cm)}}$     (A1)     (C2)

${\text{Area}} = 2\pi {(5)^2} + \pi (5)(13)$     (M1)(M1)(M1)

Notes: Award (M1) for surface area of hemisphere, (M1) for surface of cone, (M1) for addition of two surface areas. Follow through from their answer to part (a).

$= 361{\text{ c}}{{\text{m}}^2}$ ($361.283 \ldots$)     (A1)(ft)     (C4)

Note: The answer is $361{\text{ c}}{{\text{m}}^2}$ , the units are required.