Question

In this figure, ∠1 and ∠2 are located on a line.

Let m∠1=x° and m∠2=(4/5 x)°.

What is the value of x?

Answer 1

x = 100

Explanation:

1 and 2 are a linear pair and sum to 180° , that is

x +
`(4)/(5)` x = 180 ( multiply through by 5 to clear the fraction )

5x + 4x = 900

9x = 900 ( divide both sides by 9 )

x = 100