I think this should be the answer!!
Answer:

Step-by-step explanation:
To isolate r, we're going to need to do some algebraic manipulation.

Multiply both sides by r:

Divide both sides by a:

Hope this helps!
None of the triangles listed has two equal base angles or two equal side lengths, therefore: D. No triangle is isosceles.
<h3>Properties of an Isosceles Triangle</h3>
- An isosceles triangle has two base angles having equal angle measure.
- The side lengths that are opposite each of the equal base angles are also congruent to each other.
Thus, none of the triangles listed has two equal base angles or two equal side lengths, therefore: D. No triangle is isosceles.
Learn more about isosceles triangle on:
brainly.com/question/11884412