Answer:
28.27 mm squares.
Explanation:
Total Surface area of the cone is given by the circular base and the curved part of the cone. This means that there are a total of 2 parts of the shape. The following 2 expressions have to be added in order to gain the total surface area:
1) Surface Area of Cone (without base) = π*r*s.
2) Area of Circle = π*r^2.
It is given that r = 2 mm and s = 2.5 mm. Plugging in the values gives:
Total Surface Area of the Diamond Ring = π*2*2.5 + π*2^2.
Total Surface Area of the Diamond Ring = 5π + 4π = 9π = 28.27 mm squares.
This means that the total surface area is 28.27 mm square (correct to 2 decimal places)!!!