Question

In the following figure, if ∆1 + ∆2 = 100 ° , then the measure of ∆4 is equal to :​

Answer 1

Answer:

1 + ∠2 = 100° (given) But ∠1 = ∠2 (vertically opposite angles) ⇒ 2∠2 = 100° ⇒ ∠2 = 50° Also ∠2 + ∠4 = 180° (linear pair) ⇒ ∠4 = 180° – 50° = 130°