Question

In ΔABC, ∠C is a right angle. If cosB = 5/13, what is sinA?

Answer 1

Answer:

The value of sinA is $\frac{5}{13}$.

Step-by-step explanation:

ΔABC

Base = b = BC

Hypotenuse = h = AB

Perpendicular = p = AC

$\cos B=\frac{b}{h}=\frac{BC}{AB}=\frac{5}{13}$

If we rotate the triangle in such a way so that base changes from BC to AC, then:

Base = b = AC

Hypotenuse = h = AB

Perpendicular = p = BC

$\sin A=\frac{p}{h}=\frac{BC}{AB}=\frac{5}{13}$

The value of sinA is $\frac{5}{13}$.

Answer 2

Answer:

The correct answer is   Sin A  =5/13

Step-by-step explanation:

Trigonometric ratio:-

Sin∅ = opposite side /Hypotenuse

cos∅ = Adjacent side/ Hypotenuse

From the given figure, we get

Triangle ABC is a right angled triangle,

<C = 90°

To find sinA

Cos B =  Adjacent side/ Hypotenuse = 5/13

Adjacent side = 5 and Hypotenuse = 13

Adjacent side of angle B = Opposite side of angle A

Therefore,

Sin A = opposite side /Hypotenuse = 5/13

The correct answer is   Sin A  =5/13