Step 1:

The vertices of the triangle are and .

Consider the vectors u, v and w are the sides of the triangle.

The component form of a vectors u, v and w are

.

.

The magnitude of the vectors are

Step 2:

The angle between two vectors and is .

The angle between and is

.

The angle between and is

.

The sum of angles in a triangle is . \ \

. \ \

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The triangle is acute triangle. \ \

Solution:

The triangle is acute triangle.

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