Check the picture below
notice, that running a line from the center, you end up with an angle bisector to a vertex of the triangle, now, this is a "regular polygon", so, all sides are equal, for a triangle, when all sides are equal, all angles are also equal, and since the sum of all internal angles in a triangle must add up to 180°, then that means, each angle is 60°
now, you run an angle bisector through it, you end up with a 30°, 30° split, and that gives you a 30-60-90 triangle
Answer:

Step-by-step explanation:
We have been given a graph of similar triangles. We are asked to find the value of x.
Since we know that corresponding sides of similar triangles are always in same proportion, so we will use proportions to find the length of x.

Upon cross multiplying our equation we will get,
Upon distributing 4 we will get,

Let us subtract 12 from both sides of our equation.

Upon dividing both sides of our equation by 4 we will get,
Therefore, the value of x will be 12.
Can’t do 16 but here are the rest :))
20 000 is as much as 20 * 1 000, so we can write it as: 20 * 10^3
3 400 000 is as much as 34 * 100 000, so we can write it as: 34 * 10^5
The sum in scientific notation would look like this:
20 * 10^3 + 34 * 10^5
I hope that's what you meant :)