Answer:
Step-by-step explanation:
The measure of arc which the right triange cuts from the circle is this means the central angle has the same measure.
Angle with measure is inscribed angle subtended on the given arc. Its measure is half the measure of the central angle, hence
Angles with measures and
are complementary angles (add up to 90°), so
Answer: sin = ±
Step-by-step explanation:
We very well know that,
cos2A=1−2sin²A
⟹ sinA = ±
As required, set A = & cos a=
,thus we get
sin =±
∴ sin =±
= ±
since ,360° < <450°
,180° < <225°
Now, we are to select the value with the correct sign. It's is obvious from the above constraints that the angle a/2 lies in the III-quadrant where 'sine' has negative value, thus the required value is negative.
hope it helped!