#1**+1 **

Cos(X) = Cos(8/10) =0.8

Arccos(0.8) = X = 36.87 degrees.

Sin(X) = Sin(36.87) =**6/10 - This is accurate because:**

**10^2 =8^2 + 6^2**

Guest Jul 6, 2018

#2**+1 **

It is a Pythagorean triple. The length of YZ is 6, as 10^{2}-8^{2}=6^{2}

As we are concerned with the angle at X, the hypotenuse is the side XZ and the opposite is the side YZ.

Using SOHCAHTOA, we know that sinx=O/H, meaning that sinx=6/10

Therefore our answer is 6/10 or 0.6 :-)

Guest Jul 8, 2018