Math Is Fun Forum

denis_gylaev

Member

Registered: 2015-03-19

Posts: 66

Geo Triangle Sides

Two sides of an acute triangle are 8 and 15. How many possible lengths are there for the third side, if it is a positive integer?

I listed the inequalities then I found how many integers were in between the inequality (if thats the correct way to say it) which I got was 15 but that was wrong, any help?

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Geo Triangle Sides

Hi;

What inequalities did you use? I got only 4.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Bob

Administrator

Registered: 2010-06-20

Posts: 10,621

Re: Geo Triangle Sides

Call that side x.

Then x < 8 + 15
And 15 < 8 + x
And 8 < 15 + x

Then check acute using cos(angle) > 0

Bob

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob