If three of the interior angles of a convex hexagon each measure 140, a fourth angle measures 84, and the
measure of the fifth angle is 3 times the measure of the sixth angle, find the measure of the sixth angle.

Respuesta :

Answer:

The sixth angle of the hexagon is [tex]54^{o}[/tex].

Step-by-step explanation:

A convex hexagon is one that does not have equal length of sides i.e it is irregular.

Sum of angles in a polygon = (n - 2) x 180

For an hexagon, n = 6.

Sum of angles in a hexagon = (6 - 2) x 180

                                               = 4 x 180

                                               = [tex]720^{o}[/tex]

Therefore, let the sixth angle be represented by x, so that;

[tex]140^{o}[/tex] + [tex]140^{o}[/tex] + [tex]140^{o}[/tex] + [tex]84^{o}[/tex] + 3x + x = [tex]720^{o}[/tex]

[tex]504^{o}[/tex] + 4x = [tex]720^{o}[/tex]

4x = [tex]720^{o}[/tex] - [tex]504^{o}[/tex]

    = [tex]216^{o}[/tex]

x = [tex]\frac{216}{4}[/tex]

  = [tex]54^{o}[/tex]

The sixth angle of the hexagon is [tex]54^{o}[/tex].

Fifth angle = 3 x [tex]54^{o}[/tex]

                  = [tex]162^{o}[/tex]