Answer:
D. A triangle with angles measuring 75°, 60°, and 45°
Step-by-step explanation:
Given various triangle descriptions, you want to know which one describes more than one triangle.
<h3>Triangle relations</h3>
The angles and sides of a triangle satisfy a few different relations:
- angle sum — the sum of angles is 180°
- triangle inequality — the sum of the two short sides exceeds the long side
- law of cosines — c² = a² +b² -2ab·cos(C)
- law of sines — a/sin(A) = b/sin(B) = c/sin(C)
<h3>Application</h3>
A. Two sides and the included angle can be used with the Law of Cosines to find the length of the third side. That is, a single triangle is created by these measurements.
B. Sides measuring 4, 8, and 15 do not satisfy the triangle inequality, so no triangle is created by these measurements.
C. Sides measuring 6, 8, and 10 satisfy the triangle inequality, so will create a single triangle. (That triangle is a right triangle.)
D. The given angles total 180°, so could be the angle measures of any number of triangles. At least one side length must be specified in order to completely define a single triangle. These measures create more than one triangle.
