in triangle ABC ,if AB=AC and angle B=20 then find angle A
Answers
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.
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 x° 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
#SPJ2