SURFACE AREA OF PRISM ACTIVITY CRACKER

Radius, as a word, is shorter than diameter which supported my reminder that the radius is half of its diameter.To make your lesson on surface area fun AND help students really understand the concept, try adding a special 'dissection lab' day into your middle school geometry unit. When working with cylinders, students may confuse the diameter and the radius.This can be so confusing! Avoid using the words “height” or “base” without saying “height of the triangle” or “height of the prism.” Base is now and forever “area of the base” and always solved first separately.

With triangular prisms, there are so many heights and so many bases.

Height is perpendicular to the base no matter where the base sits.

Students think that height is always a vertical measurement.

Our curriculum writers, Reagan and Asheigh, recommend always solving for the area of the base first and separately and clearly label it a B.

Using the formula, students will plug in a length or width of the base instead of the total area of the base.

This helped them see that no matter which way it was facing or which shape was on the bottom didn’t matter.” They would say it was still a triangular prism. Then I would flip it over where it was laying on one of the rectangular faces and ask them what it was again. They would tell me it was a triangular prism. I would lay it in my hand where it was “sitting” on the triangle.

I love this simple idea from a member of our curriculum team, Ashleigh, “Students assume the figure is always sitting on its base, so I would hold up a triangular prism (this one was hardest for them).

Make sure to emphasize that the base must be congruent and parallel for prisms and cylinders.

Assuming the base of the figure is the face is at the bottom.

Our 8th Grade Surface Area Digital Activities provide great application opportunities. Our 7th Grade Surface Area Digital Activities do a fantastic job of breaking down the nets (see below). It can be tricky for students to see how a rectangle fits on a cylinder’s net.

In addition, bring in soup cans (cylinders) and peel off the label to show the rectangular face of a cylinder. They will see those same dimensions that form the box’s net. You can provide student groups with a 3D box, they measure the dimensions (length, width, height), and then carefully cut to form the rectangular prism’s net.

SURFACE AREA OF PRISM ACTIVITY CRACKER

Reusing amazon boxes, cereal boxes, or cracker boxes can be a great exercise to make the connection between 3D figures and their nets. In 7th grade, surface area is a brand new concept, so students will need time to understand what surface area is. If there are more quadrilaterals, then you have a triangular prism. To help students, ask, “Are there more triangles or quadrilaterals?” If there are more triangles, then you have a pyramid. Students sometimes struggled with differentiating between pyramids and triangular prisms. This will be an important distinction when they transition to calculating volume in later units. It is important to differentiate between the lateral height (which is the height of the triangular face) and the height of the pyramid. Pyramids have one base and the lateral faces all come to one point, the vertex. The pyramid is named by the shape of the base – so triangular prisms have a triangle base while rectangular pyramids have a square or rectangle as a base. Pyramids are included in 7th grade TEKS and 7th grade CCSS.Ī pyramid is composed of a base and triangular faces. This is a great time to rapidly cold call students to ask what each variable represents. You will need to repeat the phrases, “perimeter of the base,” “area of the base” and “height of the prism” until you lose your voice.

Surface area of prism activity