Since this is a right triangle, we can use one of the three main trigonometric functions: sine, cosine, or tangent.
Remember: SOH-CAH-TOA
Looking from angle I, we know the opposite side and the hypotenuse. Therefore, we should use sine.
sin(I) =
![(√(39))/(√(51))](https://img.qammunity.org/2022/formulas/mathematics/college/a1feeeb39p4pf2e0dsz00dkkknwnbks1cc.png)
To solve, you can use your calculator and the inverse sine function (sin^-1).
I = sin^-1(
)
I = 61 degrees
Hope this helps!