In this case, we'll have to carry out several steps to find the solution.
Step 01:
Data
Triangle diagram
p = ?
Step 02:
We must apply the triangle rules to find the solution.
2p + 4p + 42 = 180
6p = 180 - 42
p = 138 / 6
p = 23
The answer is:
The value of p is 23