Answer:
the unknown side is 12, and the angle y is 67.4°
Step-by-step explanation:
this is a right triangle with side 5 and hypotenuse 13. By the Pythagorean Theorem, 13² = 5² + opp², where "opp" is the side opposite Angle y.
Then 169 = 25 + opp² and so opp = √144 = 12.
Now to find the angle y:
5
cos y = ------ = 1.176 radians
13
Converting 1.176 radians to degrees, we get
1.176 180°
------- * ---------- = 67.4°
1 π rad
