Answer:
see explanation
Step-by-step explanation:
Using the double angle identity for sine
sin2x = 2sinxcosx
Consider left side
cos20°cos40°cos80°
= 
(2sin20°cos20°)cos40°cos80°
= 
(2sin40°cos40°)cos80°
= (sin80°cos80° )
= 
(2sin80°cos80° )
= . sin160°
= . sin(180 - 20)°
= . sin20°
= 
= right side , thus proven
Since all the angles are congruent, the sides must be congruent too.
So, just have one equation on one side equal to another.
5x= 3x+6
Subtract 3x from both sides.
2x=6
Divide 2 into both sides.
x=3.
We can check this by seeing if all the sides are the same.
5(3)= 15
6(3)-5= 15
3(3)+6= 15
I hope this helps!
~cupcake
Answer:
ooooooooooooooooof
Step-by-step explanation:
9514 1404 393
Answer:
m∠Y = 40°
Step-by-step explanation:
The sum of complementary angles is 90°. If we let s and y represent m∠S and m∠Y, respectively, the angle measures in degrees satisfy ...
s + y = 90
(4y -110) +y = 90 . . . . . . . . substitute for s
5y = 200 . . . . . . . . . add 110
y = 40 . . . . . . . divide by 5
The measure of angle Y is 40°.
