we know that two similar triangles will have ratio corresponding side is same.
ratio triangle 1 is 75m^2.
and triangle 2 is 12m^2.

so we have ratio of area
.
ratio of perimeter will be
.
from these perimeter ratio also
.
Since 18 is one twentieth of the angle of a full circle, 360, the circumference is 20 times the arc distance of 15, or 300
Answer:
The surface area would be 471.
I think it's t=778 not 100%