The value of sin^2 30° - cos^2 30° is

-1/2

Step-by-step explanation:

Im not going to go into detail about how to compute sin30 and cos 30, but know that sine and cosine are just the ratios between the sides of a 30-60-90 triangle with a hypothenuse of 1.

With that being said:

sin^2 30 - cos^2 30

=  (1/2)^2 - ((sqrt3)/2)^2

= 1/4 - 3/4

= -1/2

according to the triangle sum theorem, all the angles in a triangle must add up to 180 degrees. if we know one angle is already 90, we do 180-90=90. the other 2 angles must add up to 90, exactly.

step-by-step explanation: