if two vertices of an equilateral triangle be (0,0) (3,√3) find the third side
Answers
(0,3)right solution for this question
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Answer:
The possible coordinates of third vertex are : (0 , 2√3) or (3 , -√3)
Step-by-step explanation:
Let the two given vertices of equilateral triangle are :
A : (0 , 0)
B : (3 , √3)
Let the third vertex be C (x , y)
Now, since all the sides of an equilateral triangle are equal
⇒ BC = AC = AB
⇒ BC² = AC² = AB²
⇒ (x - 3)² + (y - √3)² = (x - 0)² + (y - 0)² = (3 - 0)² + (√3 - 0)²
⇒ (x - 3)² + (y - √3)² = x² + y² = 9 + 3
⇒ (x - 3)² + (y - √3)² = x² + y² = 12
First take, x² + y² = 12 .........(1)
And, (x - 3)² + (y - √3)² = 12 ...........(2)
⇒ x² + 9 - 6x + y² + 3 - 2√3y = 12
⇒ x² + y² - 6x + 12 - 2√3y = 12
⇒ 12 - 6x + 12 - 2√3y = 12
⇒ - 6x + 12 - 2√3y = 0
⇒ y = 2√3 - √3x.............(3)
Putting this value in equation (1)
x² + (2√3 - √3x)² = 12
⇒ 4x² - 12x = 0
⇒ x = 0 or x = 3
Now, from equation (3)
When x = 0 then y = 2√3
When x = 3 then y = -√3
Thus, the possible coordinates of third vertex are : (0 , 2√3) or (3 , -√3)