I like to think of radicals (or square roots) just as x terms-
here, we have the equivalent (kind of) to x * 4x.
Since these are both x terms and 4x= x*x*x*x, we can simply write 5x.
Im not sure what your teacher is asking you to communicate, but most simply would like to see evidence that you understand the material rather than simply looking up the answer... (i mean without reading an explanation xD)
4√x= √x*√x*√x*√xso √x • 4√x =5√x
There are 360 degrees in the rhombus which means the equilateral triangles has 180 degrees (because it is half the rhombus and also it is the angle sum of a triangle). It is equilateral meaning all sides and angles are the same so they all must be 60 (180/3)
Now this must mean that angle a is equal to the opposing angle being 60
well, we know that θ is in the III Quadrant, where the sine is negative and the cosine is negative as well, or if you wish, where "x" as well as "y" are both negative, now, the hypotenuse or radius of the circle is just a distance amount, so is never negative, so in the equation of cos(θ) = - (2/5), the negative must be the adjacent side, thus

