Question

If three angles of a quadrilateral are $30°,80°,110°$ the fourth angle is $120°$.

• A. True
• B. False

Answer 1

The correct option is B False

Find the fourth angle:

Let the fourth angle be $x°$
$$\begin{gathered} 30°+80°+110°+x°=360° \\ \Rightarrow 220°+x°=360° \\ \Rightarrow x=140° \end{gathered}$$
So, the fourth angle $140°\ne 120°$.
Hence, the given statement is false.