Angle properties: Angles centered at a point?

AI Thread Summary
To find the value of x in the angle problem, the angles are expressed as a=45, b=x+44, c=3x-23, and d=3x. The equation formed by summing these angles is 45 + (x + 44) + (3x - 23) + 3x = 360. Simplifying this leads to 7x + 66 = 360. Solving for x gives x = 42. The discussion emphasizes the importance of correctly summing angles centered at a point to solve for unknown variables.
Frank212
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Homework Statement


Find what x is
bandicam 2016-08-09 20-05-56-722.jpg

I don't understand what to do with (3x-23).

Homework Equations


Angles centered at a point: a+b+c+d=360

https://drtayeb.files.wordpress.com/2011/03/igcse-math-extended.pdf
(here is a pdf of the textbook, Exercise 4A, 3i.)[/B]

The Attempt at a Solution


a+b+c+d=360
45+44=89
360-89=271
two angles left to solve for final equation: 3x,x and (3x-23)
(3x-23)? <- please tell me what to do with this, do you isolate it?
 
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Clue : Sum the whole lot into an equation for x :

3x + (3x - 23) + ------- = ??
 
Frank212 said:

Homework Statement


Find what x is
View attachment 104457
I don't understand what to do with (3x-23).

Homework Equations


Angles centered at a point: a+b+c+d=360

https://drtayeb.files.wordpress.com/2011/03/igcse-math-extended.pdf
(here is a pdf of the textbook, Exercise 4A, 3i.)[/B]

The Attempt at a Solution


a+b+c+d=360
45+44=89
360-89=271
two angles left to solve for final equation: 3x,x and (3x-23)
(3x-23)? <- please tell me what to do with this, do you isolate it?
There are four angles, a=45, b= x+44, c=3x-23, d=3x. They are expressed in terms of x. Just add the angles, 45 + (x+44) + (3x-23) + (3x) = 360. You get the equation for the unknown x. Collect the like terms and solve for x.
 
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ehild said:
There are four angles, a=45, b= x+44, c=3x-23, d=3x. They are expressed in terms of x. Just add the angles, 45 + (x+44) + (3x-23) + (3x) = 360. You get the equation for the unknown x. Collect the like terms and solve for x.
Thank you ehild, your explanation really helped a lot.

45+(x+44)+(3x-23)+3x=360
7x+66=360
7x=294
7x/7=294/7
x=42
 
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Nice work!
Frank212 said:
Thank you ehild, your explanation really helped a lot.

45+(x+44)+(3x-23)+3x=360
7x+66=360
7x=294
7x/7=294/7
x=42
 
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