Length of ab the minor arc is 40 cm what is the circumference of c?

well, recall that a circle has a total of 360°.

now, that central angle of 60°, has an arc of 40 units.

well, how many 60° are there in 360°? 360/60 = 6.

well, there are 6 of those, and since each has a 40 units arc, there should also be six 40 units arcs for the whole circle, namely its circumference, 6*40.

proofs involving isosceles triangles often require special consideration because an isosceles triangle has several distinct properties that do not apply to normal triangles.(more about triangle types) therefore, when you are trying to prove that two triangles are congruent, and one or both triangles, are isosceles you have a few theorems that you can use to make your life easier.

step-by-step explanation:

an isosceles triangle has two congruent sides and two congruent angles. the congruent angles are called the base angles and the other angle is known as the vertex angle. ∠bac and ∠bca are the base angles of the triangle picture on the left. the vertex angle is ∠abc