Question: Need help with this problem

Need help with this problem

If you have an obtuse triangle with base=24 meters and area=60 square meter. How do you calculate the other sides? A line is straight down from the odtuse angle making a right angle. I know that Area=Base X hight/2 meaning 60= 24h/2 60=12h h=60/12 h=5 Is this correct? If it is, I don't know what to do next to get the sizes of the other side. The problem that I have is that the base for the two triangle which = 24 meters is uneven. I don't know what to do to get the second side. I think I have to work with the small triangle which is 45,45,90 but I only have one side which=5. I know that the hypotenuse(c)square= (a)square +(b) square. I think??? juke, you are not been a pain. Thanks very much for helping. :) Yes juke, it make sense. I'll still working on it, but it make sense. Thanks

Date Posted: September 05, 2008 Tagged Under: triangle . geometry
Rating:
n/a

No problem. Let me know if you need any other help.

Rating:
9.5

You are on the right track. I worked on it last night. With that you can now find the one side using one of two rules. One way is to use Pythagoras' theorem which states that on a right triangle the ratio is always 1:1:sqrt 2 or you can you your trigonometric functions (ie. sin, cos, tan). After you know theses two sides and the one angle, I believe you can use the law of cosines two solve for the third side: so it would look like this:

You know the base: 24 m
You know the adjacent length (by using the right triangle to be: 7.1
Using the Law Of Cosines: c^2 = a^2 + b^2 – 2ab cos C. you can than solve the third side.

Does this make sense?

Rating:
n/a

How can you figure out where the straight line intersects the 24 meter base? In other words, now that you know that h=5 and you have two right triangles, if you could find the second lengths of the two triangles, it would be easy to find the lengths. I am not sure but you may need to use one of the theorems for triangles and I haven't used those in 10+ years (congruency, etc...)

Rating:
n/a

You are correct so far. The next part is where I can't remember all the rules.

I see that you changed the tag, it's better but still not going to get out to the other members. Tags have to be separated by comas or the computer thinks it is one large sentence. In this case your tag is "Geomety-Find the sides of a triangle", which would mean that someone else would have to have the exact same phrase in order for it to be matched. What you want to do is in the tag field type the something similar to the following: geometry, math, trigonometry, triangle

This will get a lot more able people to potentially contribute. Hope this helps, I don't mean to be a pain, just trying to help. :)

Rating:
n/a

It's been so long since I've done this, I'll have to give it some thought. In the mean time you might get better response if you tag it with some more general tags. For example: math, trigonometry, etc. Questions asked are actually sent off to other members based on tag matching, so if you are too specific the question is not actually sent to anyone. I hope that helps.