# Thread: angle of the triangle

1. ## angle of the triangle

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

nedd help...

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

nedd help...
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....

3. the question is frm my maths book ..it says the answer is 144 ...

4. ...

5. 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.

6. ## Angles in a triangle

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

nedd help...
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 $8\times 18 = 144^o$.

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

nedd help...
$a=x$
$b=8x$
$c=8x$

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

8. 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.

9. ## sorry SengNee

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."