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555-605 (Medium)|   Geometry|      
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Bunuel
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In triangle ABC, AB = BC. If angle A = (4x – 30)° and angle C = (2x + 08 Dec 2020, 10:45
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25% (medium)

Question Stats:

81% (01:41) correct 19% (02:04) wrong based on 57 sessions

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In triangle ABC, AB = BC. If angle A = (4x – 30)° and angle C = (2x + 10)°, find the number of degrees in angle B.

(A) 20
(B) 40
(C) 50
(D) 60
(E) 80
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E
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Loop123
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In triangle ABC, AB = BC. If angle A = (4x – 30)° and angle C = (2x + 08 Dec 2020, 11:04
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If they are isosceles(AB=BC) then (4x – 30)°=(2x + 10)°

x=20

2(20)+10= 50
180- 50(2)=80

E
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stne
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In triangle ABC, AB = BC. If angle A = (4x – 30)° and angle C = (2x + 19 Dec 2020, 01:38
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Bunuel
In triangle ABC, AB BC = . If angle A = (4x – 30)° and angle C = (2x + 10)°, find the number of degrees in angle B.

(A) 20
(B) 40
(C) 50
(D) 60
(E) 80
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Bunuel,

Equal to sign in misplaced, making it hard to understand the question. Hope you will look into this. Thank you.
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Bunuel
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In triangle ABC, AB = BC. If angle A = (4x – 30)° and angle C = (2x + 19 Dec 2020, 02:38
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stne
Bunuel
In triangle ABC, AB BC = . If angle A = (4x – 30)° and angle C = (2x + 10)°, find the number of degrees in angle B.

(A) 20
(B) 40
(C) 50
(D) 60
(E) 80

Bunuel,

Equal to sign in misplaced, making it hard to understand the question. Hope you will look into this. Thank you.
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Edited. Thank you!
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In triangle ABC, AB = BC. If angle A = (4x – 30)° and angle C = (2x + 19 Dec 2020, 07:39
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In \(\triangle ABC, AB=BC, i.e. \angle A=\angle C\)
\(4x-30^{\circ}=2x+10^{\circ}\)
\(x=20^{\circ}\)
Now, substitute the value of \(x\) in any of the above equations, i.e. \(\angle A=\angle C = 50^{\circ}\)
\(\angle B = 180^{\circ} - (50^{\circ}+50^{\circ}) = 180^{\circ}-100^{\circ} =80^{\circ}\)
Ans E
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In triangle ABC, AB = BC. If angle A = (4x – 30)° and angle C = (2x + 20 Dec 2020, 02:12
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SOLUTION:

Since AB=BC,
4x−30=2x+10
=>x=20∘
Thus 4x-30=50 and the other angle 2x+10 should also be 50.
The third angle asked =180-(50+50)=80 (OPTION E)

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In triangle ABC, AB = BC. If angle A = (4x – 30)° and angle C = (2x + 20 Dec 2020, 09:25
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Bunuel
In triangle ABC, AB = BC. If angle A = (4x – 30)° and angle C = (2x + 10)°, find the number of degrees in angle B.

(A) 20
(B) 40
(C) 50
(D) 60
(E) 80
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That means Angle A=Angle C

or, 4x-30=2x+10

\(2x=40\)

\(x=20\)

\(A=C=2x+10=40+10=50, \ Thus \ B=80\)
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