All the angles of a triangle add up to 180 degrees.
30+39+<4= 180
69+<4= 180
Subtract 69 on both sides.
<4= 111 degrees
<1 and <4 are supplementary and adjacent. They equal 180 degrees as well.
111+<1= 180
<1= 69 degrees
I hope this helps!
<em>~kaikers</em>
Answer: 1/8, 0.13, 1/2, 7/8
Step-by-step explanation: Mental Math
We know that
sin²x+cos²x=1
so
clear cos x
cos x=(+/-)√[1-sin²x]
in this problem
<span>Angle 0 is in quadrant 1 -----> cos o and sin o are positive
</span>sin o=2/5
cos x=√[1-(2/5)²]----> cos o=√[1-4/25]----> cos o=√[21/25]---> cos o=√21/5
the answer is
cos o=√21/5
The answer should be B and A
