Question

ABCD is a cyclic quadrilateral.ifA-C=20 then find C

Answer 1

Answer:

< A = 100°

< C = 80°

Explanation :

We know that ,

In a cyclic quadrilateral, sum of opposite angles = 180°

Then, In quadrilateral ABCD

<A + <C = 180° .. (i)

Also it is given that,

<A - <C = 20°

=> <A = 20° + <C ... (ii)

From equation (I) and (ii) , we get

=> 20° + <C+ < C= 180°

=> 2<C = 160°

=> <C = 160/2 = 80°

Hence, <C = 80°

Now from equation (ii), we get

<A = 20° + <C = 20° + 80° = 100°

Hence, < A = 100°