[tex]\begin{gathered} e\text{ = 49} \\ f\text{ = 131} \\ d\text{ = 90} \end{gathered}[/tex]
Here, we want to find the marked angles
As we can see, the angle marked e and 49 degrees are opposite each other
That makes them equal since they are vertically opposite angles
Thus, e = 49
Angle marked 49 and f lie on the same straight line
Mathematically, the sum of angles on a staright line is 180
Thus;
[tex]\begin{gathered} f\text{ + 49 = 180} \\ f\text{ = 180-49} \\ f\text{ = 131} \end{gathered}[/tex]
The angle beside the angle marked d is 90 degrees
Mathematically, the sum of angles on a straight line is 180
Thus;
[tex]\begin{gathered} d\text{ + 90 = 180} \\ d\text{ = 180-90} \\ d\text{ = 90} \end{gathered}[/tex]
