(1) Right triangle (according to Pythagorean theorem)

AB=2, AC=BC= root number 2.

→ is a triangle with c as the right angle.

(2) It is a cone after rotation.

Volume: volume of cone = bottom area * height * 1/3.

The bottom area is π * r 2 = 2π.

Height = root number 2

The volume is 4π/3.

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