Question

1.the perimeter of a certain sector of circle is 20 cm.if the radius of circle is 6cm find its area of sector????
2.a cubical block of 7cm is surmounted by a hemisphere.what is the greatest diameter the hemisphere can have??find surface area of solid!!!...

Answer 1

let the angle of th sector be  Ф rad.   
perimeter = 6 Ф = 20   => Ф = 10/ 3 rad

area = π 6² * (10/3) / 2π = 60 cm²
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2.
 diameter of the hemisphere = side of cube = 7 cm
 surface area = 5 * 7² +  (7² - π 3.5²) +   (4π 3.5² )/2
                    =  294 + π 3.5²  cm²

Answer 2

here is ur ans check it out