PLEASE HELP! Two sides of a triangle have lengths of 15 and 20. The length of the third side can be any number between ____ and ____. i have a test tomorrow and i dont understand these types of questions

Question

doc.brown · Answer

|dw:1393367345103:dw|

anonymous · Answer

wait im confused

anonymous · Answer

that doesnt answer the question

anonymous · Answer

@MathLegend

anonymous · Answer

@doc.brown

doc.brown · Answer

If you pretend the mark between the 15 and 20 is a hinge, like a closing door, it might help you visualize what the third side might look like.

anonymous · Answer

how does that help me find the numbers? @doc.brown

anonymous · Answer

i know what the answer is i just dont know how to find it

doc.brown · Answer

Look at the first drawing.  It's not a triangle, it's a line.
But if you hinge it the tiniest bit it becomes a super skinny triangle.
The length of that side is ever so much smaller than 15+20.

anonymous · Answer

yeah i see that but i still dont know how to get the numbers

doc.brown · Answer

Look at the last drawing.  It's not a triangle, it's a line.
But if you hinge it back it becomes the smallest bit longer that 20-15.

anonymous · Answer

so 5 and 35

anonymous · Answer

but my answer key says 3, 15

doc.brown · Answer

|dw:1393368168878:dw|

anonymous · Answer

yeah but thats not the answer

doc.brown · Answer

I don't know then.  Perhaps someone else might agree your book is wrong.  Unless there is a picture, or some piece of information we are missing, this answer makes sense to me.

doc.brown · Answer

Also,
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3 won't reach!

anonymous · Answer

oh sorry! i was reading the wrong one thanks so much for the help!!

doc.brown · Answer

lol, no problem, always happy to help

doc.brown · Answer

ps, if you're stuck, draw a picture

anonymous · Answer

thanks so much!