# angle of the triangle

• April 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)
• April 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 $a,b,c$.

$a+b+c=180^o$

$a=8b$

$b=8c$

Therefore,
$a=64c$

The largest angle is $a$.

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

$a+b+c=180$

$a=8b=8c$

Then $a=144^o$

Very sorry, my english is not so good.
(Worried)(Worried)(Worried)
• April 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 $x^o$, then the largest angle is $8x^o$. So:

$x +x+8x =180$

$\Rightarrow 10x = 180$

$\Rightarrow x = 18$

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

• April 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)

$a=x$
$b=8x$
$c=8x$

$x + 8x + 8x = 180$
$17x = 180$
$x = 180/17 = 10.588$
Largest angle $= 8x = 84.70$
• April 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.
• April 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."