Question

Line $l||m$ and Line $p||q$ and two angles are given as ${45}^o\text{and}{75}^o$. Then value of $x+y$ is

• A. ${30}^o$
• B. ${100}^o$
• C. ${120}^o$
• D. None

Answer 1

The correct option is C ${120}^o$

Given that line $p$ is parallel to line $q$,
$x={45}^o\left(\text{alternate int. angles theorem}\right)$

Also given that line $l$ is parallel to line $m$,
$y={75}^o\left(\text{alternate int. angles theorem}\right)$
Now,
$x+y={45}^o+{75}^o$
$x+y={120}^o$
Hence, option$\left(c\right)$ correct.