Find the area of the triangle whose vertices are : `(a cos alpha, b sin alpha), (a cos beta, b sin beta), (a cos gamma, b sin gamma)`

Using determinant find the area of the triangle whose vertices are (a cos alpha ,b sin alpha ), (a cos beta, b sin beta ) and (a cos gamma, b sin gamma ).

The orthocentre of triangle formed by (a cos alpha,a sin alpha),(a cos beta,a sin beta),(a cos gamma,a sin gamma) is

If origin is the orthocentre of the triangle with vertices A(cos alpha,sin alpha),B(cos beta,sin beta),C(cos gamma,sin gamma) then cos(2 alpha-beta-gamma)+cos(2 beta-gamma-alpha)+cos(2 gamma-alpha-beta)=

Delta ABC has vertices A(a cos alpha,a sin alpha),B(a cos beta,a sin beta) and C(a cos gamma,a sin gamma) then its orthocentre is

If origin is the orthocentre of a triangle formed bythe points (cos alpha, sin alpha,0), (cos beta, sin beta,0), (cos gamma, sin gamma,0) then sumcos(2alpha-beta-gamma)= -

If (0,0) is orthocentre of triangle formed by A(cos alpha,sin alpha),B(cos beta,sin beta),C(cos gamma,sin gamma) then /_BAC=

If (0,0) is orthocentre of triangle formed by A(cos alpha,sin alpha),B(cos beta,sin beta),C(cos gamma,sin gamma) then /_BAC is

If origin is the orthocenter of a triangle formed by the points (cos alpha*sin alpha,0)*(cos beta,sin beta.0),(cos gamma,sin gamma,0) then sum cos(2 alpha-beta-gamma)=