HELP MATH GEOMETRY!!!! I DO NOT KNOW WHAT TO DO!!!

Noah is baking a two-layer cake, in which the bottom layer is a circle and the top layer is a triangle. If segment AB = 6 inches and arc AB≅ arc AC, what does Noah know about the top layer of his cake?

Circumscribed circle D around triangle ABC, arcs AB and AC are congruent.

Question 7 options:

segment AB is twice the length of segment BC because their arcs are congruent; therefore, ΔABC is an equilateral triangle.

segment AB is twice the length of segment BC because their arcs are congruent; therefore, ΔABC is an isosceles triangle.

segment AB ≅ segment BC because their arcs are congruent; therefore, ΔABC is an equilateral triangle.

segment AB ≅ segment BC because their arcs are congruent; therefore, ΔABC is an isosceles triangle.

* Let's revise some facts in the circle- If a circle is circumscribed around a triangle, then the vertices of the triangle divide the circle into three arcs- The three sides of the triangle are the chords of the circle,

Each chord in the circle is subtended by an arc-

If two arcs are equal, then they are subtended as equal chords*

Let's solve the problem,

Circumscribed circle D around triangle ABC,

The vertices of triangle ABC lie on the circumference of the circle AB, BC, AC are the chords of the circle,

Arcs AB and AC are congruent,

Arc AB ≅ arc AC, Arc AB subtended the chord AB, Arc AC subtended the chord AC, AB = AC, AB = 6 inches, AC = 6 inches,

The triangle with two equal sides is called an isosceles triangle, Δ ABC is an isosceles triangle,

Noah knows that the top layer of his cake is an isosceles triangle* segment AB ≅ segment BC because their arcs are congruent; therefore, ΔABC is an isosceles triangle.

segment AB ≅ segment BC because their arcs are congruent; therefore, ΔABC is an isosceles triangle ⇒ answer D.