Question

In the given figure, PQ, RS and UT are parallel lines. If c = 75° and a = (2/5)c, then find b + d/2.​

Answer 1

We have, c=75∘

∴a=52c=52×75∘=30∘

Now, UT∥PQ

⇒c=a+b (Alternate angles)

⇒75∘=30∘+b⇒b=75∘−30∘=45∘

Also, PQ∥RS

∴b+d=180∘ (Co-interior angles)

⇒d=180∘−45∘=135∘

So, b+2d=45∘+2135∘=45∘+67.5∘=112.5∘