Question

If the diameter of the base circle of a cone is equal to 54 cm and the generator is 13 cm, then the area of the axial section will be.

Answer 1

answer is 786 cm2 anwer is this so

Answer 2

GIVEN :

Cone with diameter of the base circle of a cone is 54 cm; generator is 13 cm

TO FIND :

Area of the axial section.

SOLUTION:

◆Axial section of a cone is an isosceles triangle.

◆Since base of the cone is 54cm, and generators are 13cm.

◆Area of the axial section ; of the isosceles triangle is ,

◆According to herons formula,

A = √[s(s-a)(s-b)(s-c)]

◆Where s is semi perimeter , a,b,c are sides.

Here a= b = 13cm, c =54cm

◆S = (a+b+c)/2 = 13+13+54 /2 = 40

◆Substituting values,

Area, A = √[40(40-13)(40-13)(40-54)]

= 638.39 sq m.

ANSWER :

Area A, 638.39 sq m