Question

the diagram shows a triangle.
what is the value of b?
b = \square^\circ

Explanation:

Step1: Sum triangle angles to 180°

$30^\circ + 119^\circ + (18b+12)^\circ = 180^\circ$

Step2: Simplify left side sum

$30 + 119 + 12 + 18b = 180$
$161 + 18b = 180$

Step3: Isolate the term with b

$18b = 180 - 161$
$18b = 19$

Step4: Solve for b

$b = \frac{19}{18}$

Answer:

$b = \frac{19}{18}$ or approximately $1.06$