Answer:
b = 5√3
Explanation:
I would honestly just use pythag, but I'll use trig:
tanθ = opposite/adjacent
tan(30°) = 5/b
btan(30°) = 5
b = 5/tan(30°)
b = 5/(√3/3) = 15/√3
b = 15/√3 · (√3/√3) = 15√3/3
b = 5/√3
Check with pythag:
a² + b² = c²
5² + 5√3² = 10²
25 + 25(3) = 100
25 + 75 = 100 ✅
I hope this helps!