Which type of triangle is formed by joining the vertices a(-3, 6), b(2, 1), and c(9, 5)?
a.
an equilateral triangle
b.
an acute scalene triangle
c.
a right triangle
d.
an obtuse scalene triangle

An obtuse scalene triangle

Step-by-step explanation:

First, we calculate the length of the sides:

Side a – the distance between points B and C – is:

Side b – the distance between points C and A – is:

Side c – the distance between points A and B – is:

Then, we calculate the measure of the angles:

None of the sides are equal, so the triangle is not equilateral nor isosceles. None of the angles are 90°, so the triangle is not right. One of the angles is greater than 90°, so the triangle must be obtuse scalene.