Question

If sin ( 20°+0) = cos 30°, then find the value of 0

Answer 1

Two angles are said to be complementary of their sum is equal to 90° .

θ & (90° - θ) are complementary angles

SOLUTION :

GIVEN:

sin (20 + θ) = cos 30°

cos (90 - (20+θ) = cos 30°

[cos (90 - θ) = sin θ]

cos (90- 20 - θ) = cos 30°

cos (70 - θ ) = cos 30°

70° - θ = 30°

70° -30° = θ

40 ° = θ

Hence, the value of θ is 40°.

HOPE THIS WILL HELP YOU

Answer 2

Given that :

sin(20°+A) = cos30°

=> sin(20°+A) = cos(90°-60°)

=> sin(20°+A) = sin60° 【 cos(90°-A) = sinA 】

=> 20°+A = 60°

=> A = 60°-20°

=> A = 40°

So, the value of A will be 40°

I hope it will be helpful for you ☺