Answer:
The size of each of the three equal unknown angles is
.
Step-by-step explanation:
Let the the unknown angle be represented by x. The polygon is a hexagon, which has three sides and angles.
sum of angle in the hexagon = (n - 2) x

n = 6, so that;
Sum of angle in the hexagon = ( 6 - 2) x

= 4 x

=

Therefore;
x + x + x +
+
+
=

3x +
=

3x =
-

3x =

x =

The size of each of the three equal unknown angles is
.