Find the four angles of a cyclic quadrilateral `A B C D` in which `/_A=(2x-1)o` , `/_B=(y+5)o\ \ /_C=(2y+15)o` and `/_D=(4x-7)o` .

Find the angles of a cyclic quadrilateral ABCD in which /_A=(4x+20)^(@),/_B=(3x-5)^(@),/_C=(4y)^(@) and /_D=(7y+5)^(@).

In a cyclic quadrilateral ABCD/_A=(2x+4)o,quad /_B=(y+3)o,quad /_C=(2y+10)o,quad /_D=(4x-5)0. Find the four angles.

If ABCD is a cyclic quadrilateral in which /_A=(x+y+10)^(@),/_B=(y+30)^(@),/_C=(x-y-20)^(@) and /_D=(x+y)^(@). Find x and y.

In a cyclic quadrilateral A B C D if A B C D a n d /_B=70^0, find the remaining angles.

ABCD is a cyclic quadrilateral such that ∠A=( 4y+20 )°, ∠B=( 3y−5 )°, ∠C=( −4x)° and ∠D=( -7x+5 )° . Find the four angles.

In a quadrilateral A B C D , given that /_A+/_D=90o . Prove that A C^2+B D^2=A D^2+B C^2 .

In a cyclic quadrilateral ABCD ,/_A=(2x+4)^(@),/_B=(x+10)^(@),/_C=(4y-4) and /_D=(5y+5)^(@). Find the values of x and y hence find all the angles.

The diagonals of quadrilateral A B C D ,A C and B D intersect in Odot Prove that if B O=O D , the triangles A B C and A D C are equal in area. GIVEN : A quadrilateral A B C E in which its diagonals A C and B D intersect at O such that B O = O Ddot TO PROVE : a r( A B C)=a r( A D C)