GEOMETRIC SHAPE NAMES

•  Many geometric shapes are named based on the number of sides that they have. If you learn the meaning of the number prefixes, it can be like a secret code that helps you know the meaning of other complex words that use the same   prefixes.

• Triangles have three sides and three angles. The prefix tri- means three. Words that use the prefix tri- usually have something to do with three parts. For example, a tripod is a camera stand that has three legs. A triathlon is a difficult sports event in which the competitors have to participate in three different activities, such as running, swimming, and bicycling.

• Quadrilaterals have four sides and four angles. The prefix quad- means four. A quadrant is a graphing chart with four sections. Dirt bikes with four wheels are called quads. The muscles in your arms that connect in four places are called quadriceps.

• Pentagons have five sides and five angles. The prefix penta- means five. A pentagram is a five-pointed star.  Poetry measured in groups of five syllable pairs is called pentameter.

• Octagons have eight sides and eight angles. The prefix oct- means eight.  An octopus has eight tentacles. A musical   octave has eight notes.  Octuplets are eight babies who are born at the same time to the same mother.

 Name:__________________________________

Answer the following questions based on the reading passage. Do not forget to go back to the passage whenever necessary to find or confirm   your answers.

1)  How do prefixes help you understand the meaning of new words?

2)  What do words that begin with tri- have in common?

3)  A duet is a song performed by two people. Based on the meaning of the prefix, what do you expect the word octet to mean?

4)  Triple is three times the amount. Based on the meaning of the prefix, what do you  expect the word quadruple  to mean?

5)  A decagonhas ten sides. Why do we call a decimal a decimal?