Question

Four friends Ravi, Mohan, Kunal & Nikhil are business partner based at RAEBARELI. They started
their journey by car to attend a meeting in LUCKNOW. After covering some distance on the
highway, they got diversion due to some repair work on highway. They left the highway at an
angle x, taken a straight pitch road of 4 km then turned at 900 and covered 3 km straight and
join the highway again at an angle y as shown in figure.
Choose the correct one: (a)x=900+y (b)y-x=900 (c)x+y=900 (d) x-y=1800

Answer 1

Given: figure 1.

Solution:

Know that from the figure the diversion is making a triangle.

Understand that, An exterior angle of a triangle is equal to the sum of its two opposite non-adjacent interior angles.

Observe that,

$\[\angle y\]$is an exterior angle and the two opposite non-adjacent angles are $\[\angle x\,\,and\,\,{90^ \circ }\]$respectively.

Therefore,

The correct equation will be,

$\[\begin{array}{l}y = x + {90^ \circ }\\ \Rightarrow y - x = {90^ \circ }\end{array}\]$

Hence, the correct answer is option (b).