Question

Using the information shown in figure, find the measures of $\angle$a, $\angle$b and $\angle$c.

Answer 1

c + 100^∘ = 180^∘ (Linear angle property)
⇒ c = 80^∘
Now, b = 70^∘ (Vertically opposite angles)
a + b + c = 180^∘ (Angle sum property)
⇒ a + 70^∘ + 80^∘ = 180^∘
⇒ a + 150^∘ = 180^∘
⇒ a = 30^∘
Hence, the values of a, b and c are 30^∘, 70^∘ and 80^∘respectively.