Area of 2D and 3D Shapes

Students learn how to calculate the area of triangles, parallelograms and trapeziums.  They use this knowledge to later find the total surface of cuboids and prisms.

This topic takes place in Term 2 of Year 8 and is the prerequite topic for Circles, Cylinders and Circular Shapes.


Area of 2D and 3D Shapes Lessons


Prerequisite Knowledge
  • Derive and apply formulae to calculate and solve problems involving: perimeter and area of triangles, parallelograms, trapezia, volume of cuboids (including cubes) and other prisms
  • Calculate and solve problems involving: perimeters of 2-D shapes and composite shapes.

Key Concepts
  • The area of a triangle is the product of its perpendicular height and base divided by two. ¬†Students often forget to divide by two.
  • To find the area of a composite shapes students should break it down into its individual components.
  • When identifying individual components of a composite shape students tend to look for triangles and rectangles rather than trapezia and parallelograms.
  • To find the surface of a cube or cuboid students could draw the net and work out the composite area.
  • More able students could derive the formula for the surface are of a cuboid.


Working mathematically

Develop fluency

  • Use language and properties precisely to analyse 2-D and 3-D shapes

Reason mathematically

  • Begin to reason deductively in geometry,

Solve problems

  • Select appropriate concepts, methods and techniques to apply to unfamiliar and non-routine problems.

Subject Content

Shape

  • Derive and apply formulae to calculate and solve problems involving: perimeter and area of triangles, parallelograms, trapezia, volume of cuboids (including cubes) and other prisms
  • Calculate and solve problems involving: perimeters of 2-D shapes and composite shapes.

 

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes:

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Mr Mathematics Blog

Practical Tips for Using Mini-Whiteboards in a Mathematics Lesson

In this blog I will share some practical tips for using mini-whiteboards in a mathematics lesson.  I use mini-whiteboards nearly every lesson because they help the students show me the progress they are making.  When I understand what the misconceptions are I am able to address them in subsequent examples as part of my feedback.  […]

Showing Progress during a Mathematics Lesson

Demonstrating student progression during a mathematics lesson is about understanding the learning objective and breaking that down into explicit success criteria. Using Success Criteria Take, for example, a lesson on calculating the area of compound rectilinear shapes. The intended learning objective was written on the main whiteboard. Success criteria were used to break down the individual […]

Plotting and Interpreting Conversion Graphs

Plotting and interpreting conversion graphs requires linking together several mathematical techniques.  Recent U.K. examiner reports indicate there are several common misconceptions when plotting and interpreting conversion graphs.  These include: drawing non-linear scales on the x or y axis, using the incorrect units when converting between imperial and metric measurements, taking inaccurate readings from either axis not […]