SalvageDiver Loc: Huntington Beach CA

I think this is an excellent question for a 7 yr old. The question wasn't asking for a right or wrong answer, but 'an answer' and the students reasoning for his/her answer. It doesn't even matter if the student knows what a right triangle is. It's just an exercise in critical thinking. The "right" math answer is well beyond the skill set of most 7 year olds.

If it were my daughter, I would just say to her, "Sweetie, your teacher just wants an answer, it could be true or it could be false. That's not what's important. All the teacher wants to know is why you chose your 'own' answer."

Personally, I think the University Math lecturer who's struggling with how to explain this to his young daughter has lost his way as a teacher. He seems intent on explaining the "right math" solution vs teaching his daughter "critical-thinking" so that she can learn to solve the problem on her own.

To get the "right" answer is a little more complicated and probably difficult for most adults also. It does require the basic concepts of geometry and calculus, reducing the geometry down to the infinitely small to answer this question. And there are a number of ways to explain your answer.

Robertjerl explained one method. As you zoom in on the intersection of the line to the circle, the geometry may approach a right triangle, but it will "never" reach it. I can also think of other ways to prove, such as using tangents or rectangle vs trapeziods.

Dannj

What’s the difference between “infinitely small” and “extremely small”?

adrianpd

All the comments regarding the appropriate math or logic skills misses the obvious issue. This is aimed at students in the UK. The skepticism is perfectly appropriate when considering most American seven year olds I suspect.

2Dragons Loc: The Back of Beyond

I used to love (NOT) those questions in Math. If the train is going 75 miles an hour, and it is 87 miles between station A and Station B, and the tracks are 4'8" apart, what time is it in Brussels? No wonder I flunked Math. I have no problem with Math in actual, practical application, but those wacko questions really did me in.

markngolf Loc: Bridgewater, NJ

We can appreciate your feeling about those type problems. Fortunately there are brilliant scientists and mathematicians who can solve them even with 1000 other twists and conditions. The landing of Perseverance on Mars was not luck.
No, I'm definitely not one of them!!
Mark

Mike from Point

There are two right angles. They start as right angels but quickly change.

josquin1 Loc: Massachusetts

I'm confused.

2Dragons Loc: The Back of Beyond

Join the Club.

robertjerl Loc: Corona, California

Hey, it's working!!!!!!

Curmudgeon Loc: SE Arizona

No it's not! This post has been hijacked by bunch of people who have nothing better to do on a Saturday

It is a simple straight forward logic question to stimulate a 7 year old girl's mind. For any normal individual, engineers and mathematicians excluded, the answer is no.

Wyantry Loc: SW Colorado

Riiight. Except you are wrong. Any gradeschooler can see the closer you get to the ends of the arc/semicircle the closer you get to right angles! (If the straight line is a diameter).

josquin1 Loc: Massachusetts

Now I'm getting more confused.

Curmudgeon Loc: SE Arizona

...the closer you get to right angles? Explain the me, as if I were 7 years old, what right angles are and why these are either right angles or not.

jayluber Loc: Phoenix, AZ

Just asking - what's the Tangent of a 0 deg angle? the intersection of the semicircle with the base line? I think it's zero degrees. SOH CAH TOA ..Opposite over the adjacent. Therefore, the arc intersects the straight line at a 90 deg angle.
Who needs to be fired???

robertjerl Loc: Corona, California

It's working = confusion on the part of some people.