They get 2/3 because 2 divided by 3=2/3.
For two triangles to be congruent by AAS:
1- Two angles in the first triangle must be equal to two angles in the second triangle
2- A non included side in the first triangle is equal to a non included side in the second triangle
Now, let's check our options. We will find that:
For the two triangles UTV and ABC:
angle T = angle A
angle V = angle C
TU (non-included between angles T & V) = AB (non-included between angles A & C)
Therefore, we can conclude that:
Triangles ABC and UTV are congruent by AAS
Answer:
the correct answer is the 3rd one
Volume of a cone = (1/3) x Area of the base (B) x height(h)
V = (1/3)·420·180
= 25200 mm³