Math, asked by nihalps7, 1 year ago

in triangle ABC ,if AB=AC and angle B=20 then find angle A

Answers

Answered by Sauron
4

Answer:

Angle A is 140°

Step-by-step explanation:

Consider angle A as x

Refer the given attachment

Angle B = Angle C as AC = AB

x + 20° + 20 = 180° [Angle Sum Property]

x + 40° = 180

x = 180 - 40

x = 140

Therefore, the value of angle is 140°.

Verification:

Check if sum of all angles of triangle ABC is 180°

20° + 20° + 140°

180°

Hence, the answer is correct.

Attachments:
Answered by barnadutta2015
2

Answer: The correct answer is 140°. Angle A is 140° in triangle ABC ,if AB=AC and angle B=20°.

Step-by-step explanation:

Let the measure of angle A be in ΔABC.

Now, ∠ B = ∠ C as AC = AB  (if two sides of a triangle is equal then their corresponding angles will be equal)
∠A+∠B+∠C = 180°

⇒ x° + 20° + 20 = 180° [Angle Sum Property]

⇒x° + 40° = 180°

⇒x° = 180° - 40°

x° = 140°

Therefore, the value of angle is 140°.

Verification of our answer:

We will check if sum of all angles of triangle ABC is 180°

⇒ 20° + 20° + 140° = 180°

Hence, the answer is correct that ∠A is 140°.

To know more, click here:
https://brainly.in/question/9039350
https://brainly.in/question/10009589


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