Find the sum of the given angles in the figure below?

enter image source here

1 Answer
Jul 29, 2017

180^@

Explanation:

enter image source here

Draw a line joining vertex C and vertex D, as shown in the figure.

In DeltaCDH, anglef+angleg+angleh=180^@
In DeltaBEH, angleb+anglee+angleh=180^@
=> angleb+anglee=anglef+angleg

In DeltaACD, anglea+anglec+angled+anglef+angleg=180^@
=> anglea+anglec+angled+angleb+anglee=180^@

Sol. 2) See Fig 2
enter image source here

In DeltaACG, angleAGC=180-(anglea+anglec)
=> angleFGE=anglea+anglec

In DeltaBDF, angleBFD=180-(angleb+angled)
=> angleGFE=angleb+angled

In DeltaEFG, anglea+angleb+anglec+angled+anglee=180^@

Hnece, the sum of the five interior angles in a 5-point star
= anglea+angleb+anglec+angled+anglee=180^@