If θ is an acute angle and sin (θ + 18°) =

Home » Aptitude » Trigonometry » Question

If θ is an acute angle and sin (θ + 18°) = (1 / 2) , then the value of θ in circular measure is :

sin (θ + 18°) =	1	= sin 30°
	2

⇒ θ + 18° = 30°
⇒ θ = 30° – 18° = 12°
∵ 180° = π radian

∴ 12° =	π	× 12
	180

=	π	radian
	15

	π	radians
	12

	π	radians
	15

	2π	radians
	5

	3π	radians
	13