question about parallelogram

[cecilia_p]

if the sides in a parallelogram are 3 cm and 5 cm can the diagonal in the parallelogram be 10 cm? 8 cm? 4 cm? why?

 

[Deleted member 4993]

if the sides in a parallelogram are 3 cm and 5 cm can the diagonal in the parallelogram be 10 cm? 8 cm? 4 cm? why?

Think about "sides of a triangle". What is possible and not possible there?

 

[topsquark]

if the sides in a parallelogram are 3 cm and 5 cm can the diagonal in the parallelogram be 10 cm? 8 cm? 4 cm? why?

Make a sketch. Can you have a triangle with a sides 3 cm and 5 cm with a diagonal of 10 cm? What would the triangle have to look like?


-Dan

 

[pka]

if the sides in a parallelogram are 3 cm and 5 cm can the diagonal in the parallelogram be 10 cm? 8 cm? 4 cm? why?

Do you know as well as understand the triangle inequality?

 

[The Highlander]

if the sides in a parallelogram are 3 cm and 5 cm can the diagonal in the parallelogram be 10 cm? 8 cm? 4 cm? why?

Do you know as well as understand the triangle inequality?

​

Imagine for yourself (in your mind's eye) what happens to the length of side c as the vertex C moves up and down.

 

[Harry_the_cat]

Forget all the theory. Get out a pen and a ruler and try to draw them!

 

[The Highlander]

Forget all the theory. Get out a pen and a ruler and try to draw them!

Why would s/he need to draw anything when the answer is obvious from the final (red) line in post #5?

 

[Harry_the_cat]

It's obvious for us, but I think you get a better feel for it, and are therefore more likely to remember it, if you put pen to paper. Call me old-fashioned!!

 

[tri]

 

[pka]

It's obvious for us, but I think you get a better feel for it, and are therefore more likely to remember it, if you put pen to paper. Call me old-fashioned!!

It could be the case that no pen and ruler are allowed, think an ACT type test.
The question is clearly testing the concept of the triangle inequality.

 

[The Highlander]

It's obvious for us, but I think you get a better feel for it, and are therefore more likely to remember it, if you put pen to paper. Call me old-fashioned!!

You're Old-Fashioned.
But your advice is always purr-dy good.

 

[Harry_the_cat]

It could be the case that no pen and ruler are allowed, think an ACT type test.
The question is clearly testing the concept of the triangle inequality.

Yeah sure but if the poster can post on a math help site, they surely have access to a pen and ruler.