Question

Find the measurement of the first and third angles if the ratio of the three consecutive angles of a cyclic quadrilateral is 1:2:3

Answer 1

Let the first three angles be
x , 2x, and 3x

recall that in any cyclic quad , the opposite angles add up to 180°
So, wouldn't x and 3x be opposite angles ?

so ......

Answer 2

x+3x=180
4x =180
x =180÷4
x =45
First angle = 45
Third angle = 3×45
= 135