Question

In $△$ABC, $\angle$ A=${50}^{\circ }$ and $\angle$ B=${60}^{\circ }$ ,then the value of x is and y is.

• A. ${110}^{\circ }$
• B. ${100}^{\circ }$
• C. ${70}^{\circ }$
• D. ${120}^{\circ }$
• E. ${80}^{\circ }$

Answer 1

Answer: (A), (C)

The correct options are
A ${110}^{\circ }$
C ${70}^{\circ }$

Given in $△$ABC, $\angle$ A=${50}^{\circ }$ and $\angle$ B=${60}^{\circ }$.
By Angle sum property of a traingle:
$\angle$ A + $\angle$ B + $\angle$ C = ${180}^{\circ }$
$\Rightarrow$ ${50}^{\circ }$ + ${60}^{\circ }$ + y = ${180}^{\circ }$
$\Rightarrow$ y = ${180}^{\circ }$ - ${110}^{\circ }$= ${70}^{\circ }$
x and y form a linear pair, i.e.,
$\Rightarrow$ x + y = ${180}^{\circ }$
$\Rightarrow$ x + ${70}^{\circ }$ = ${180}^{\circ }$
$\Rightarrow$ x = ${110}^{\circ }$