To solve this, it might be easier to draw it out (see the picture below). I split it into two triangles and used trig functions to find the altitude. I used the big triangle to find theta, and the used theta to find the side of the altitude. *remember that sine= opposite/hypotenuse*
To find out if the triangle is a right triangle, we must check if the following equation is true:

on the left side, we have:

and on the right side, we have:

since on both sides we get 625, we have that the brace forms a right triangle.
Step-by-step explanation:
<em>Hello</em><em>,</em><em> </em><em>there</em><em>!</em><em>!</em><em>!</em>
<em>The</em><em> </em><em>answer is option</em><em> </em><em>D</em><em>.</em>
<em>I</em><em> </em><em>have</em><em> </em><em>given</em><em> </em><em>solution</em><em> </em><em>on</em><em> </em><em>the</em><em> </em><em>picture</em><em>.</em>
<em>Hope it helps</em><em>.</em><em>.</em><em>.</em><em>.</em><em>.</em>
Each term is being divided by -3, so the next three terms would be:
-1/3, 1/9, -1/27
Its a , i had it yesterday and i got everything right dont worry :))