Final answer:
By calculating the distance between points A(-1, 2), B(4, 2), and C(3, -1), we find that two sides of the triangle are equal, meaning the triangle is an isosceles triangle.
Step-by-step explanation:
To classify the triangle formed by points A(-1, 2), B(4, 2), and C(3, -1) by its sides, we need to calculate the length of each side using the distance formula: the square root of the sum of the squares of the differences in the x-coordinates and y-coordinates. After calculating these lengths, we can determine the type of triangle by comparing the side lengths.
First, we find the distance AB, which is simply the horizontal distance between A and B, as they share the same y-coordinate. Thus, AB = 4 - (-1) = 5 units.
Next, we calculate the distance AC using the distance formula:
AC = √[(-1 - 3)² + (2 - (-1))²] = √[(-4)² + 32] = √[16 + 9] = √25 = 5 units.
Lastly, we calculate the distance BC:
BC = √[(4 - 3)² + (2 - (-1))²] = √[1 + 32] = √[1 + 9] = √10 ≈ 3.16 units.
Since two sides AB and AC are equal, the triangle is an isosceles triangle.