Question 1009810
The radius of a sphere is 21 cm. Find the volume of a spherical wedge whose lune base angle is 90 degree.
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&nbsp;&nbsp;&nbsp;&nbsp;A spherical wedge is a solid formed by revolving a semi-circle about its diameter by less than 360°. 

&nbsp;&nbsp;&nbsp;&nbsp;Spherical Lune is the curve surface of the wedge, it is a surface formed by revolving a semi-circular arc 
&nbsp;&nbsp;&nbsp;&nbsp;about its diameter by less than 360°. 

&nbsp;&nbsp;&nbsp;&nbsp;See more at: <A HREF=http://www.mathalino.com/reviewer/solid-mensuration-solid-geometry/spherical-wedge-and-spherical-lune>http://www.mathalino.com/reviewer/solid-mensuration-solid-geometry/spherical-wedge-and-spherical-lune</A>.
</pre>


The volume of this "solid body" is one fourth of the volume of the sphere of the radius 21 cm:


V = {{{1/4}}}.{{{(4/3)*pi*R^3}}} = {{{1/3}}}.{{{3.14*21^3}}}.