Finding Area in Different Ways: Sentence Starters and Frames

Some ideas for sentence frames/starters that could be incorporated into your lesson are listed below.  If you think a sentence frame/starter will be helpful, consider how it will support students’ mathematical learning and/or development of academic language, and decide which sentence frame/starter (from the list below or that you create) would best support students’ learning. You may find that the starters and frames vary in level of difficulty, and plan to provide them to students accordingly.


(Problem 1)

In order to calculate the area of the polygons, I


(Problem 2)

To make a triangle with an area of 12 square units, the third vertex of the triangle must be placed so that


To find triangles with an area of 12 square units, I



(Problem 1)

In order to find the area of the polygons, it is helpful to create or draw __________________________ around the polygons.

It is helpful to know area formulas of _____________________________ to solve for the areas of the polygons.


Academic Language

Students should have opportunities to see, hear, and write key mathematical ideas during this activity. There are some specific terms that students need to understand in order to engage in this task, and there are some additional terms and phrases that may surface as the students engage with the task. You may think of additional words or phrases that are key to this activity.  As the task is introduced, solved by the students, and discussed, ensure that students have opportunities to experience (i.e., through discussion, pictures, and the use of gestures) and to build understanding for key words and phrases. Examples of words and phrases that may be involved in work on this problem include:

  • break down or decompose the figure into triangles and rectangles
  • base of the triangle
  • height of the triangle
  • obtuse triangle
  • right triangle
  • isosceles triangle
  • count
  • either side of the Y-axes
  • reflect the triangle
  • different; at least; vertices; located at; possible positions; convincing; change
  • subtract; remove