# angle of the triangle

• Apr 27th 2009, 09:16 PM
hi00000
angle of the triangle
calculate the largest angle of a triangle in which one angle is eight times each of the others.

nedd help...(Crying)
• Apr 27th 2009, 09:23 PM
SengNee
Quote:

Originally Posted by hi00000
calculate the largest angle of a triangle in which one angle is eight times each of the others.

nedd help...(Crying)

Let these angles are $\displaystyle a,b,c$.

$\displaystyle a+b+c=180^o$

$\displaystyle a=8b$

$\displaystyle b=8c$

Therefore,
$\displaystyle a=64c$

The largest angle is $\displaystyle a$.

Erm....I'm not sure....Please tell me either I'm right or not....
(Thinking)(Thinking)(Thinking)
• Apr 27th 2009, 09:29 PM
hi00000
the question is frm my maths book ..it says the answer is 144 ...
• Apr 27th 2009, 09:31 PM
hi00000
...
• Apr 27th 2009, 10:11 PM
SengNee
Quote:

Originally Posted by hi00000
the question is frm my maths book ..it says the answer is 144 ...

Maybe the question means:

$\displaystyle a+b+c=180$

$\displaystyle a=8b=8c$

Then $\displaystyle a=144^o$

Very sorry, my english is not so good.
(Worried)(Worried)(Worried)
• Apr 27th 2009, 11:26 PM
Angles in a triangle
Hello hi00000
Quote:

Originally Posted by hi00000
calculate the largest angle of a triangle in which one angle is eight times each of the others.

nedd help...(Crying)

If the smaller angles are both $\displaystyle x^o$, then the largest angle is $\displaystyle 8x^o$. So:

$\displaystyle x +x+8x =180$

$\displaystyle \Rightarrow 10x = 180$

$\displaystyle \Rightarrow x = 18$

So the largest angle is $\displaystyle 8\times 18 = 144^o$.

• Apr 28th 2009, 01:11 PM
razemsoft21
Quote:

Originally Posted by hi00000
calculate the largest angle of a triangle in which one angle is eight times each of the others.

nedd help...(Crying)

$\displaystyle a=x$
$\displaystyle b=8x$
$\displaystyle c=8x$

$\displaystyle x + 8x + 8x = 180$
$\displaystyle 17x = 180$
$\displaystyle x = 180/17 = 10.588$
Largest angle $\displaystyle = 8x = 84.70$
• Apr 28th 2009, 06:14 PM
SengNee
Quote:

Originally Posted by razemsoft21
a=x
b=8x
c=8x

x + 8x + 8x = 180
17x = 180
x = 180/17 = 10.588
Largest angle = 8x = 84.70

Should be

a=8x
b=x
c=x

Because there is only one largest angle that is 8 times larger than the other two angles.
• Apr 28th 2009, 10:31 PM
razemsoft21
sorry SengNee
Quote:

Originally Posted by SengNee
Should be

a=8x
b=x
c=x

Because there is only one largest angle that is 8 times larger than the other two angles.

you may be right, But the original writer says
"the question is frm my maths book ..it says the answer is 144 ... "
depending on understanding the question
the idea of solving it depend on (the sum of angles of any triangle is 180 degrees."