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^@#