Answer:
Triangle RST is an equilateral triangle.
Explanation:
All three sides of the triangle are of equal length, therefore, because an isosceles triangle is when 2 sides of the triangle are the same length, a scalene triangle being when all sides are of different lengths, and a right triangle having a right angle (a 90 degree angle), this only leaves equilateral, all three sides being the same length, like in the triangle shown.