Q. 174.9( 10 Votes )

In Fig. 4, from t

Answer :


We have to find the surface area of the frustum BCQP.


Given: AR = 4cm


AD = 12cm


ARQ = ADC = 90°


A = A (common)


ΔAQR ΔACD (by AA)



QR = 2cm


Radius of the bigger cone = R = 6cm


Radius of the smaller cone = r = 2cm


Height of the frustum = RD = 12-4 = 8cm


Slant height of the frustum:


l = √(R-r)2 + h2


l = √ (6-2)2 + 82


l = √ 16 + 64 = √80 = 4√5 = 4 × 2.236 = 8.944cm


Total surface area of frustum =


= =


= 350.591cm2


Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
caricature
view all courses