Can you solve this geometry problem for nine year olds?

  • Context: High School 
  • Thread starter Thread starter andrewkirk
  • Start date Start date
  • Tags Tags
    Geometry School Year
Click For Summary
SUMMARY

The geometry problem presented involves finding the angle x in a triangle with known angles of 50, 30, and 20 degrees. The solution, derived using trigonometric functions, reveals that x is approximately 30 degrees. However, participants in the discussion argue that the problem should be solvable without trigonometry, emphasizing the importance of constructing isosceles triangles and utilizing properties of vertical angles. The discussion highlights the complexity of the problem, suggesting it may be too advanced for a typical nine-year-old student.

PREREQUISITES
  • Understanding of basic triangle properties, including the sum of interior angles being 180 degrees.
  • Familiarity with isosceles triangles and their properties.
  • Knowledge of vertical angles and their equality.
  • Basic trigonometric concepts, particularly the arctan function.
NEXT STEPS
  • Research the properties of isosceles triangles and their applications in geometry.
  • Study the concept of vertical angles and their significance in solving geometric problems.
  • Explore methods for constructing geometric figures to simplify problem-solving.
  • Learn about the historical context and significance of problems like "Langley's Adventitious Angles."
USEFUL FOR

Mathematics educators, primary school teachers, and anyone interested in enhancing their understanding of geometry and problem-solving techniques suitable for young learners.

  • #31
Man this is an old thread.
And I can't remember now if I solved this problem.
Quite the "head scratcher", as I recall.

llober said:
See next figure, what happes here?

No.

Charles Link said:
In the diagram of @OmCheeto of post #18, ADEC is a 4 sided polygon, with enough information available that, using the law of cosines and law of sines

That's cheating, according to the OP.

andrewkirk said:
Does anybody out there think they can solve it without using trig?

hmmm... Wondering if hdroogling with quotes works on a mac?

answer: Yes. And that appears to be the only instance of a "Hail Mary" on my computer. hmmmm...
 

Similar threads

High School New solutions to old, historic problems
  • · Replies 2 ·
Replies
2
Views
2K
High School Calculating trigonometry without calculator?
  • · Replies 8 ·
Replies
8
Views
2K
High School Reprise: Calculate the distance between two points without using a coordinate system
  • · Replies 1 ·
Replies
1
Views
2K
High School How Tall is the Tower in This Classic 1957 Math Problem?
  • · Replies 1 ·
Replies
1
Views
1K
High School Graphing arccosine: What if we use different domains?
  • · Replies 7 ·
Replies
7
Views
2K
High School Problem solving with hyperbolic functions
  • · Replies 3 ·
Replies
3
Views
1K
Should I double up on math courses next school year?
  • · Replies 5 ·
Replies
5
Views
3K
High School Basic geometry question re isosceles triangles
  • · Replies 3 ·
Replies
3
Views
3K
High School Can You Solve This Simple Geometry Problem with Just a Ruler and Pencil?
  • · Replies 23 ·
Replies
23
Views
3K
MHB Helping my daughter study for a Trig test....
  • · Replies 3 ·
Replies
3
Views
2K