#1

I need to find the perimeter of a triangle given the area, height, and two sides.

It's probably a super simple question/solution, but math in general is not one of my favorite(because I'm no good at it) subjects.

Anyways:

Area=924 sq cm

Height=24 cm

Side 1=40 cm

Side 2=51 cm

Not looking for the

Thanks for any and all help!

It's probably a super simple question/solution, but math in general is not one of my favorite(because I'm no good at it) subjects.

Anyways:

Area=924 sq cm

Height=24 cm

Side 1=40 cm

Side 2=51 cm

Not looking for the

*answer*, just how to do it.Thanks for any and all help!

#2

I might be able to help, which side is the base?

#3

Use the Pythagorean Theorem to find the length of the third side, then add all 3 sides up

I'm assuming the base of the triangle is the side not given, amirite?

I'm assuming the base of the triangle is the side not given, amirite?

*Last edited by mcjosh at Jan 6, 2010,*

#4

U need to see that a triangle is just half of a square or rectangle. Figure the sides of the rectangle that the triangle is cut from and you should be able to be the final side of the triangle.

#5

Draw a line straight down fromthe top angle to the base, creating 2 right triangles. Then, use Pathagoreans theorim to solve for the missing side. (a^2 + b^2 = c^2 when C is the hypotenuse and A and B are the other 2 legs)

*Last edited by gatechballer at Jan 6, 2010,*

#6

Or I guess you could do a-squared+b-squared=c-squared

#7

Yea the unknown side is the base. I can't believe I forgot about the Pythagorean Theorem but my teacher didn't mention it even though now it makes complete sense. Thanks guys

*Last edited by TheElectricity at Jan 6, 2010,*

#8

Yea the unknown side is the base. I can't believe I for got about the Pythagorean Theorem but my teacher didn't mention it even though now it makes complete sense. Thanks guys

Yup

#9

Area=(base x height)/2

924=(base x 24)/2

1848=base x 24

base=77

77+51+40=168

Unless I'm completely wrong, you don't need to use Pythagoras at all.

924=(base x 24)/2

1848=base x 24

base=77

77+51+40=168

Unless I'm completely wrong, you don't need to use Pythagoras at all.

#10

Yea the unknown side is the base. I can't believe I for got about the Pythagorean Theorem but my teacher didn't mention it even though now it makes complete sense. Thanks guys

yeah so you'll have to find the missing sides of the 2 smaller triangles that you created to get the entire base length......then obviously add the sides (I hope you knew that last part haha)

#11

Area=(base x height)/2

924=(base x 24)/2

1848=base x 24

base=77

77+51+40=168

Unless I'm completely wrong, you don't need to use Pythagoras at all.

Oh wait Hes right! This is much quicker (both ways work though). However, the height given must be the lenght from the missing side to the opposite angle.

#12

Doppelgänger has the best approach.

OP, if you want to check your work use Hero's Formula.

http://en.wikipedia.org/wiki/Heron%27s_formula

OP, if you want to check your work use Hero's Formula.

http://en.wikipedia.org/wiki/Heron%27s_formula

#13

Doesn't the Pythagorean Theorem only work with right triangles?