Answer:
3/5
Step-by-step explanation:
sin theta=opposite/hypotenuse
4/5=opposite/hypotenuse
therefore opposite=4 and hypotenuse=5
for adjacent
using pythagoras theorem
a^2+b^2=c^2
opposite^2 + adjacent^2 =hypotenuse^2
4^2 + adjacent^2 =5^2
16 + adjacent^2 =25
adjacent^2 =25-16
adjacent =
adjacent=3
cos theta=adjacent/hypotenuse
=3/5
therefore the value of cos theta is 3/5
This is a proof that the angles in a triangle equal 180°:
The top
line (that touches the top of the triangle) is
running parallel
to the base of the triangle.
So:
<span> <span>angles A are the same </span> <span>angles B are the same </span> </span>
And you can easily see that A + C + B does a complete rotation from one side of the straight line to the other, or <span>180°</span>
