Draw a line at the base of the polygon.The two known exterior angles are (90*2).Each of the remaining exterior angles: 3x=360-180 =180 degrees x=180/3 =60 degrees
Extend the lines. All exterior angles add up to 360 degrees. So angle a and angle b is 90 degree each. So their exterior angle is 90 degrees each. 360 degree-180 degrees equal 180 degrees. 180 degrees is the total exterior angle for 3 (x). So one exterior angle for (x) is 180 degree divide by 3 which is 60 degrees.So 180 degree minus 60 degrees is 120 degrees. (Angles on a st. line)(x)
extend the lines for each sides. angle a =180º -90º =90º angle a = angle b =90º all exterior angles add up to 360º 3(X)=360º -90º -90º =180º x=180º ÷3 =60º xº=180º-60º =120º
First, extend all the lines. As angle A & B are both 90 degree, that means that the exterior angle of both angle A and B are 90 degree respectively. Since the all exterior angle adds up to 360 degree, we use 360 degree to minus ( 90 x 2 ) which is equal to 180 degrees. This 180 degree refers to the 3 exterior angle of angle x. Therefore, to find one angle x, we will have to use 180 degrees divide by 3 which is 60 degree and use 180 degree to minus 60 degree where angle x is 120 degree as there are angles on a straight line
Step1: Extent the line at the base of the triangle. Angles on a st. line=180* 180*-90*=90*(the exterior angle point A) Step2: Angle EAB=Angle CBA=90* Exterior angle at A is also= exterior at B All exterior angles=360* Step3: 3x=360*-90*-90* =180* x=180*/3 =60* Ans: 60 degrees
Extend the lines of each sides. All the exterior angles will add up to 360 degrees. Angle A and Angle B's exterior angles are 90 degrees each. Why 90 degrees? It is because when you extend the lines, it is a straight line. And the interior angle is 90 degrees. Thus 180 degrees - 90 degrees = 90 degrees. We have 2 90 degrees exterior angles. So to find the remaining three exterior angles.
360-(90x2)= 180 degrees
The three remaining angles are both X degrees. This means that their exterior and interior degrees are all the same. So how to find each of the X's exterior angle?
180 divide by 3 = 60 degrees :D
So each of the exterior angle is 60 degrees. Now we can proceed on to find the degree of angle "X". When we extend the line, it is a straight line. A straight line is 180 degrees.
extend a line from the interior angle.on the bottom of the polygon the interior angle is 90 degrees therefore the exterior angle will be also 90 degrees (angles on a straight line)since all the exterior angles add up to 360 degrees we can then subtract 180 degrees from 360 degrees leaving us with 180 degrees which we then divide by 3 to find x.
find the total sum of all the angels by (n-2)x180 when n is the no of sides of the polygon so the totals sum of the inyterior angles is (5-2)x180 =3x180 =540 so we take the sum of all the interior angels minus angles EAB and CBA which are both 90 degress to get the sum of the three unknown angles 540-90-90 =360 so 360 degrees is the sum of the 3X's and we take 360 to devide by 3 3X=360 X=360/3 =120 so X equals 120 degrees
exterior concept =360/n Find the number of side which is 5. then take the 180'-90=90(angles ABC & EAB) A regular polygon exterior angle= 360/5=72 angles ABC+EAB= 90+90=180 regular polygon,2 sides=72+72=144 180-144=36(overshot by) 72+72=216(remainding,suppose to be) 216-36=180(-overshot) 180/3=60(x) ans=60'
Let's see. ... ... First, using the 'general' concept found in the textbook, take (n-2)x180, to find the sum of all interior angles. (where 'n' is the number of sides of the polygon) Therefore! (n-2)x180 =(5-2)x180 =540 Then, take 540 minus off angles A and B, which are both 90. Therefore! <-- love this word. 540-(90x2) =540-180 =360 Now, 360= 3x x= 360/3 = 120 <---thus, the answer.
28 comments:
i think if u wanna find the unknown value, u got to divide the diagram into rectangle and triangle.
Draw a line at the base of the polygon.The two known exterior angles are (90*2).Each of the remaining exterior angles:
3x=360-180
=180 degrees
x=180/3
=60 degrees
Extend the lines. All exterior angles add up to 360 degrees. So angle a and angle b is 90 degree each. So their exterior angle is 90 degrees each. 360 degree-180 degrees equal 180 degrees. 180 degrees is the total exterior angle for 3 (x). So one exterior angle for (x) is 180 degree divide by 3 which is 60 degrees.So 180 degree minus 60 degrees is 120 degrees. (Angles on a st. line)(x)
Extend the side lines. Draw and angle sign at each line . all exterior angles add up to 360degrees.
angle B and A adds up to 180degrees.
so ..
360-180= 180 ( 3 ext. angles )
180 / 3 = 60 ( each ext. angles )
thus .
x = 180 - 60
= 120 ( int. + ext. = 180)
answer : x = 120degrees
Extend each side so that we can see the exterior angles.
All exterior angles of an regular polygons add up to 360 degree.
The exterior angle of Angle EAB and Angle BCA is both 90 degree.
180-90=90
90 x 2 = 180 degree
Both Exterior Angle of Angle EAB AND CBA is 180 degree.
To find the Exterior angles of the unknown angles x is to take :
360 - 180 = 180 degree
(ext. Angle sum of polygon)
One exterior angle of unknown angle x
= 180 degree divide by 3
= 60 degree
Unknown angle x
= 180 - 60
= 120 degree (Angles on st. line)
extend the lines for each sides.
angle a =180º -90º
=90º
angle a = angle b
=90º
all exterior angles add up to 360º
3(X)=360º -90º -90º
=180º
x=180º ÷3
=60º
xº=180º-60º
=120º
answer=120º
First, extend all the lines. As angle A & B are both 90 degree, that means that the exterior angle of both angle A and B are 90 degree respectively. Since the all exterior angle adds up to 360 degree, we use 360 degree to minus ( 90 x 2 ) which is equal to 180 degrees. This 180 degree refers to the 3 exterior angle of angle x. Therefore, to find one angle x, we will have to use 180 degrees divide by 3 which is 60 degree and use 180 degree to minus 60 degree where angle x is 120 degree as there are angles on a straight line
sum of exterior angles=360º
to find the sum of the three exterior angles of x,
360º-(2*90º)=180º
one exterior angle of x=180º/3=60º
x=180º-60º=120º
Step1: Extent the line at the base of the triangle.
Angles on a st. line=180*
180*-90*=90*(the exterior angle point A)
Step2: Angle EAB=Angle CBA=90*
Exterior angle at A is also= exterior at B
All exterior angles=360*
Step3:
3x=360*-90*-90*
=180*
x=180*/3
=60*
Ans: 60 degrees
Extend the lines of each sides.
All the exterior angles will add up to 360 degrees. Angle A and Angle B's exterior angles are 90 degrees each. Why 90 degrees? It is because when you extend the lines, it is a straight line. And the interior angle is 90 degrees. Thus 180 degrees - 90 degrees = 90 degrees. We have 2 90 degrees exterior angles. So to find the remaining three exterior angles.
360-(90x2)= 180 degrees
The three remaining angles are both X degrees. This means that their exterior and interior degrees are all the same. So how to find each of the X's exterior angle?
180 divide by 3 = 60 degrees :D
So each of the exterior angle is 60 degrees. Now we can proceed on to find the degree of angle "X". When we extend the line, it is a straight line. A straight line is 180 degrees.
(Int. + Ext. degree)- Ext. degree = 180 degrees - 60 degrees
= 120 degrees.
The final answer is 120 degrees :D
xoxo,
Puay Shan
1 Diligence
extend a line from the interior angle.on the bottom of the polygon the interior angle is 90 degrees therefore the exterior angle will be also 90 degrees (angles on a straight line)since all the exterior angles add up to 360 degrees we can then subtract 180 degrees from 360 degrees leaving us with 180 degrees which we then divide by 3 to find x.
HELLO MR LIM(:
alright!
how to slove?
easy.
SOLUTION :
draw a ling across,[EC]
to make a triangle and a square.
then from there draw another line at the base of the polygon,and then you know that the exterior angles,is 90 degrees each.
a 5-sided polygon has 5 angles,which is a total of 360 degrees.
thus,
3x = 360-180
= 180 degrees
therefore,
x = 180/3
=60 degrees.
FINALLY-
angle x = 60 degrees,
its exterior is 120 degrees(:
sorry mr lim,
i deleted the other one cause i changed my post name,
its nothing vulgar,
i just reposted(:
oh,and i'm from 1diligence(:
Firstly, extend the lines for each side of the polygon, so as to see the exterior angles.
The exterior angles of both angle BAE and angle ABC are 90º, as seen by,
180º-90º=90º [angles on a st. line]
The sum of all the exterior angles of a regular polygon add up to 360º.
The sum of the exterior angles of angle BAE and angle ABC is 180º, as seen by,
90ºx2=180º
The sum of three exterior angles, namely angles AEB,EDC and DCB is then 180º, as seen by,
360º-180º=180º [three exterior angles]
180º÷3=60º [one exterior angle]
Unknown angle x
= 180º-60º
=120º
Answer: 120º
Done By: MELANIE HENG(6)
Class: 1 Diligence
Dear Mr Lim,
I am postind as my class's HMT blog account because i do not have a blog account. Please take note!(:
find the total sum of all the angels by
(n-2)x180 when n is the no of sides of the polygon
so the totals sum of the inyterior angles is
(5-2)x180
=3x180
=540
so we take the sum of all the interior angels minus angles EAB and CBA which are both 90 degress to get the sum of the three unknown angles
540-90-90
=360
so 360 degrees is the sum of the 3X's and we take 360 to devide by 3
3X=360
X=360/3
=120
so X equals 120 degrees
er mr lim index12 is me,cherie i used the wrong account
exterior concept =360/n
Find the number of side which is 5. then take the
180'-90=90(angles ABC & EAB)
A regular polygon exterior angle=
360/5=72
angles ABC+EAB= 90+90=180
regular polygon,2 sides=72+72=144
180-144=36(overshot by)
72+72=216(remainding,suppose to be)
216-36=180(-overshot)
180/3=60(x)
ans=60'
lets see......
extend lines, then since exterior angles = 360 degrees,
360- (90*2)
because of the two right angles
then, 180 divide 30 for each exterior angle. u get 60..
then, 180-60
for x
x=120
Let's see.
...
...
First, using the 'general' concept found in the textbook, take (n-2)x180, to find the sum of all interior angles. (where 'n' is the number of sides of the polygon)
Therefore!
(n-2)x180
=(5-2)x180
=540
Then, take 540 minus off angles A and B, which are both 90.
Therefore! <-- love this word.
540-(90x2)
=540-180
=360
Now,
360= 3x
x= 360/3
= 120 <---thus, the answer.
Oh yeah. This is Ingrid, who is from 1 Faith.
P.S Thanks to Cherie for helping me out.
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