Three students attempt to define what a circle is. Can you match the teacher's comments to the definitions?

Ruby's definiton: A 3-dimensional shape whose boundary consists of all points equidistant from a fixed point (the center).

Shriya's definition: The set of all points in a 2D plane such that for every point in the set there is exactly one other point in the set that is d (call it diameter) units away.

Abhishek's definition: The set of all points in a plane that are the same distance (radius) away from some given point (center).

answers: Are you thinking of a sphere?

You are correct. Nicely done!

This is incorrect. For example, your definition also allows for the following shape, which is just part of a circle.

1mile equals approximately 1.6 kilometers. which best approximates the number of miles in 6 kilometers?

If you are dealt 4 cards from a shuffled deck of 52? cards, find the probability that all 4 cards are diamondsdiamonds.

Nthe opening scene of the movie raiders of the lost ark, indiana jones replaces a golden statue with a bag of sand. the platform on which the statue is placed is designed to detect the mass of the statue. if the bag of sand has a different mass than the statue, then a mechanism triggers and destruction ensues. the density of gold is about 20\text{ g/cm}^320 g/cm 3 20, space, g, slash, c, m, start superscript, 3, end superscript. the density of sand can be estimated at 2.5\text{ g/cm}^32.5 g/cm 3 2, point, 5, space, g, slash, c, m, start superscript, 3, end superscript. the gold statue can be modeled as a cylinder with height 25\text{ cm}25 cm25, space, c, m and radius 8\text{ cm}8 cm8, space, c, m. in terms of \piπpi, what is the mass of sand indiana jones needs to avoid triggering the mechanism?