You know that the total measure of the angles in a triangle is 180 degrees.
You can use this to find angles x and y.
The angles of one of the triangles are x, 104, and 64. This means x would be 12.
104+64+x = 180
x = 180-104-64
x = 12
Use this same method to find y. The angles of the triangle y is in are 84, 59, and y. This means y is 37.
84+59+y = 180
y = 180-84-59
y = 37
Now you have x and y. The angles x, y, and z share one triangle. You can use this to find z.
x+y+z = 180
You know that x is 12 and y is 37.
12+37+z = 180
z = 180-12-37
z = 131
So...
x = 12
y = 37
z = 131
