Chapter 1.3, Problem 1PSA

To determine

To Find: The measure of the $\angle ABC$ .

Answer to Problem 1PSA

  $\angle ABC=134°$

Explanation of Solution

Given:

  

Concept Used:

Sum of linear pair of angle is $180°$

Calculation:

Since, the sum of linear pair of angle is $180°$

  $\begin{array}{l}\angle ABC+\angle DBC=180°\\ \Rightarrow \left(3x+8\right)°+\left(x+4\right)°=180°\\ \Rightarrow 4x=180°-12°\\ \Rightarrow 4x=168°\\ \Rightarrow x=42°\\ \Rightarrow \angle ABC=\left(3\times 42+8\right)°=134°\\ \therefore \angle ABC=134°\end{array}$

Conclusion:

  $\angle ABC=134°$