Ineed to find out x y and z and am very lost and confused !

X^2 = 6^2 + 17^2
x^2 = 36 + 289
x^2 = 325
x = 18.0277563773

1/2 Vertex angle = arc tan (6/17)
1/2 Vertex angle = arc tan (0.3529411765 )
1/2 Vertex angle = 19.44 Degrees

So, the other "half of the vertex angle = 90 - 19.44 degrees = 70.56

cosine (70.56) = 17 / z
z = 17 / cosine (70.56)
z = 17 / 0.33282
z =  51.0786611382

half of y^2 = 51.0786611382^2 - 17^2
half of y^2 = 2609.0296236711 -289
half of y^2 = 2,320.03
half of y = 48.1666858282
y = 48.1666858282 + 6
y = 48.1666858282

wow - lots of work!!

69 i think because is the only one square

The answer is 63.!