Given right triangle ABC with right angle b and cos(3x+30) = sin (12x). If angle A is (3x+10) what is the value of angle A

Answer 1

The sum of the measures of all the angles in a triangle is always equal to
180o.

In a right triangle, however, one of the angles is already known: the right angle, or the 90o angle.

Let the other two angles be x and y (which will be acute).

Applying these conditions, we can say that,

x+y+90o=180o
x+y=180o−90o
x+y=90o

That is, the sum of the two acute angles in a right triangle is equal to
90o.

If we know one of these angles, we can easily substitute that value and find the missing one.

For example, if one of the angles in a right triangle is 25o, the other acute angle is given by:

25o+y=90o

y=90o−25o

y=65o

Answer 2

I was askin for angel A, also the triangle isnt right, idk why but it keeps putting it as right traingle

Answer 3

Like I said before, all triangles add up 180o, so:
Use 180o and subtract the two other angles.
Then, you have the answer of the unknown angle.

Answer 4

If you recall:
cos k = sin (90 - k) and sin p = cos (90-p)

given: cos(3x + 10) = sin(12x)

cos(3x+10) = sin (90 - 3x - 10)
but we are given that: cos(3x+10) = sin(12x)

so 12x = 80-3x
15x = 80
x = 80/15 = 16/3

so angle A = 3x+10
= 3(16/3) + 10 = 26°
which would make angle B = 64°