Question

23. What is the value of a? The diagram is not to scale.

Answer 1

I may give the answer, but not the proper calculation so aware.

So we all know a triangle have 180 degree.

We have 180 - (2a + 6) - a = 90

So abandon the 6 and 90 at this point, we'll have 2a and a

180 - 90 - 6 = 84

84 / 3 = 28.

So a = 28, 2a + 6 = 62

90 + 28 + 62 = 180, which makes the answer valid.