Question

The triangle formed by joining the points A(-2 , 2), B (4 , 2) and C(1 , 6) is .

• A. isosceles
• B. right angled
• C. scalene

Answer 1

The correct option is A isosceles

The distance between two points $(x_1,y_1)\text{and}(x_2,y_2)$ is given by $\sqrt{(x_2-x_1{)}^2+(y_2-y_1{)}^2}.$

$\text{AB}=\sqrt{(4-(-2){)}^2+(2-2{)}^2}=6\text{units}$
$\text{BC}=\sqrt{(4-1{)}^2+(2-6{)}^2}=5\text{units}$
$\text{CA}=\sqrt{(-2-1{)}^2+(2-6{)}^2}=5\text{units}$

Since BC = AC, $\Delta ABC$ is an isosceles triangle.