Answer:
11.34464...
Explanation:
it is not a 3-dimensional cone, it is a 2-dimensional segment of a circle. and you need to find its area.
which is also why you are asked to find the area, because for a 3-dimensional object you would have been asked about the volume of the surface.
now, about a circle and its segments.
you know how to get the area of a circle ?
it is pi×r²
that is for the full circle.
you know how many degrees it is to go "full circle" ?
360 degrees.
so, here we have only a segment of 52 degrees out of the full 360 degrees.
in other words we are dealing with 52/360 = 13/90 of the full circle.
all we have to do is therefore multiply the area of the full circle with that fraction, and we have our result.
pi×r²×13/90 = pi×5²×13/90 = pi×5×13/18 = 11.34464...