Question

a triangle abc with ab = 10 cm, bc = 5 cm, angle a = 30 degrees and right - angled at c. there are four options: tan(30°) = 5/b, tan(30°) = b/5, tan(30°) = 10/b, tan(30°) = b/10

Explanation:

Step1: Recall tangent - ratio definition

$\tan\theta=\frac{\text{opposite}}{\text{adjacent}}$

Step2: Identify sides for }30^{\circ}

For $\angle A = 30^{\circ}$, opposite side is 5 cm and adjacent side is $b$.

Answer:

$\tan(30^{\circ})=\frac{5}{b}$