Check whether (5, – 2), (6, 4) and (7, – 2) are the vertices of an isosceles triangle.
Let the points (5, −2), (6, 4), and (7, −2) represent the vertices A, B, and C of the given triangle respectively.
AB=\(\sqrt{(5-6)^2+(-2-4)^2}=\sqrt{(-1)^2+(-6)^2}=\sqrt{1+36}=\sqrt{37}\)
BC=\(\sqrt{(6-7)^2+(4-(-2))^2}=\sqrt{(-1)^2+(6)^2}=\sqrt{1+36}=\sqrt{37}\)
CA=\(\sqrt{(5-7)^2+(-2-(-2))^2}=\sqrt{(-2)^2+0}=2\)
Therefore, AB=BC
As two sides are equal in length, therefore, ABC is an isosceles triangle.
Determine if the points (1, 5), (2, 3) and (– 2, – 11) are collinear
In a classroom, 4 friends are seated at points A, B, C and D. Champa and Chameli walk into the class and after observing for a few minutes Champa asks Chameli, “Don’t you think ABCD is a square?” Chameli disagrees. Using the distance formula, find which of them is correct.
| Case No. | Lens | Focal Length | Object Distance |
|---|---|---|---|
| 1 | \(A\) | 50 cm | 25 cm |
| 2 | B | 20 cm | 60 cm |
| 3 | C | 15 cm | 30 cm |