[verroq]

Not really

1. Construct a triangle ABC. Construct a line parellel to AB through C. Alternate angles and angle sum of triangle shows it is 180 degrees

2. Use congruent triangles

3. A number of ways doing this. I would cut it into two triangles

4. 360/6 = 60 degrees. Thus each sector is a equilateral triangle.

5. 100 pi

6. Basic algebra, let x be the length of the perpendicular. x = 12, solve for sides using Pythagoras. 20 and 15

7. x : x^2

Would expect to be year 7 or year 8 level.

[kingkilr]

Yep, the algebra was frankly also elementary school level IMO.

[tjarratt]

Algebra isn't normally taught at the elementary school level. Now, I'd argue that it SHOULD be, so students can choose to study some interesting fields of mathematics after grade 5, but that's a different argument entirely.

If I remember correctly, my school district didn't offer true algebra until 8th grade, for honors students only, in a class that started an hour before any regular class. Hardly elementary.

[kingkilr]

I'll grant you my elementary school math was better than most, but I think the point that this isn't very advanced stands.

[younata]

When I was in middle school (5 years ago), algebra was standard 8th grade math. Honor students got 2 years of algebra from 7th to 8th grade.

At least, my year was given two years of algebra.