CBSE Class 10 Answered

We assume you are refering to the following problem statement.

NCERT Class X, Chapter 3, Ex. 13.1 Q3.

Solution.

Total surface area of the toy = Curved surface area of the cone + Curved surface area of the hemisphere.

= πrl + 4πr²/2

= πrl + 2πr²

Height of the cone = total height - radius of the hemisphere = 15.5 - 3.5 = 12 cm

Slant height of the cone, l  = (12² + 3.5²) = 156.25 = 12.5 cm

Hence

TSA = πrl + 2πr²

= (3.14)(3.5)(12.5) + 2(3.14)(3.5)²

= 137.38  + 76.93

= 214.31 cm²

Regards,

Team,

TopperLearning.