The measure in degrees of GR is 80 degrees
How can the angle be calculated?
A triangle has three vertices and three edges, making it a three-sided polygon. The fact that a triangle's internal angles add up to 180 degrees is its most significant characteristic. This characteristic is known as the triangle's angle sum property, when considering handling trigonometry
It should be noted that the line GR=GV
Then we know the angle as
angle G = 20 degree
180 - 20 = 160. ( total angle in a triangle is 180 degree
line GR=GV
160 / 2 = 80.
Then the require angle = 80 degree