Question

what is the value of b? b - 4° b + 38° b

Explanation:

Step1: Apply exterior - angle property

The exterior - angle of a triangle is equal to the sum of the two non - adjacent interior angles. So, $b + 38^{\circ}=(b - 4^{\circ})+b$.

Step2: Simplify the equation

Expand the right - hand side: $b + 38^{\circ}=b - 4^{\circ}+b$. Combine like terms: $b + 38^{\circ}=2b-4^{\circ}$.

Step3: Solve for b

Subtract b from both sides: $38^{\circ}=2b - b-4^{\circ}$. Then $38^{\circ}=b - 4^{\circ}$. Add $4^{\circ}$ to both sides: $b=38^{\circ}+4^{\circ}$.

Answer:

$b = 42^{\circ}$