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Grade 10Algebra

If the length of diagonal of regular pentagon is b and side length is a,prove that

a^2/b^2+b^2/a^2=3 ???


Profile image of Sathya
14 Years agoGrade 10
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1 Answer

Profile image of Shyama P
14 Years ago

consider right triangle AOB

angle OAB =54 degree

sin54=b/2a

b=2asin54

sub in eq.

a2/(4a2sin254) + (4a2sin254)/a2 =3