Surface Area of Cylinders & Prisms Vocabulary Surface Area of Cylinders & Prisms

Surface Area of Cylinders & Prisms Radius Surface Area

Cylinder A solid object with: Two identical flat ends that are circular or elliptical One curved side. It has the same cross-section from one end to the other.

Prism A solid object with two identical ends and flat sides: The sides are parallelograms (4-sided shape with opposites sides parallel) The cross section is the same all along its length The shape of the ends give the prism a name, such as "triangular prism"

Radius The distance from the center to the circumference of a circle. It is half of the circle's diameter.

Surface The outside layer of an object. It has area but no thickness. It is a two-dimensional boundary that can be flat or curved.

Area The size of a surface. The amount of space inside the boundary of a flat (2-dimensional) object such as a triangle or circle.

Bonus Teasers No paper, pencils, or pens. BRAINS ONLY!!! (and maybe eyes so you can see the problems…oh, and a mouth so that you can tell me the answers…and a hand, so that you can raise your hand…)

A girl, a boy, and a dog start walking down a road A girl, a boy, and a dog start walking down a road. They start at the same time, from the same point, in the same direction. The boy walks at 5 km/h, the girl at 6 km/h. The dog runs from boy to girl and back again with a constant speed of 10 km/h. Every 15 minutes, the boy and girl stop and reat for 3 minutes. The dog does not slow down on the turn. How far does the dog travel in 1 hour? 10 kilometers. Duh.

There are 999 people in the town, from bald to 998 hairs. The founders of Hairytown decreed years ago that: No two people can have the same number of hairs No one can have 999 hairs. No one can have more, or the same, number of hairs as the population of the town The town has now reached its maximum population - what is it? There are 999 people in the town, from bald to 998 hairs.

A 1-meter stick is broken into two pieces at random A 1-meter stick is broken into two pieces at random. What is the length of the shorter piece, on average? The shorter piece will be randomly from 0cm to 50cm long, because if it’s more than 50cm, it’s not the shorter piece. The average of 0cm and 50cm is 25cm.

If it were two hours later than now, it would be half as long until midnight as it would be if it were an hour later. What time is it now? 9PM

If I drive half-way to the city at 30 km/hour, how fast do I have to go for the rest of the way to make the average speed for the entire journey of 60 km/hour? Example: It is 120 km to the city You get halfway (60 km) at 30 km/h, which takes 2 hours. To make it all the way (120 km) at 60 km/h would take 2 hours ... but you have already been driving for 2 hours, so your time is up. You should be there already!  You are half way there, and want to double your average, so your speed would have to be infinite.