Lesson Plan – Parallelograms, Kites, Trapeziums.
Objectives and Habits of Mind
Level 4 - To accurately measure the length and width of rectangles to the nearest mm.
Level 5– To find the area and perimeter of rectangle using formula.
Level 6 – To find the area of triangles, parallelogram, rhombuses and trapeziums using formula.
•I can work well in a group, listening attentively and taking on different roles when needed.
•I can negotiate and follow ground rules, to ensure fairness and cooperation when working with others.
•I can identify the best information to help complete a task and put it into my own words.
Keywords: Area, Base, Height, Formula
Mental and Oral Starter
Pupils to complete the table provided by drawing a picture of each polygon and writing in the formula for finding
the area. Once they have had a go at doing this on their own give them a copy of a correct completed table to
stick into their books.
Main Activity
Demonstrate how to find the area of kites, parallelograms and trapeziums using slides 7-10 to
prove how / why the formulas work. Give out the ‘today’s task’ instruction sheet to each group and
briefly talk through the instructions with the class. Make sure that pupils understand their role.
Discuss the learning outcomes and explain that the anyone working out the rectangular parts of
the house should also calculate the perimeters. Give each group slides 13-15 to cut out and fit
together to make the house. Remind pupils that they should refer to their formula sheet they
completed as the starter activity and make sure they show all their working out.
Plenary
Pupils to reflect on the success criteria for the Habits of Mind and Maths Objectives
LO To find the area of other polygons RAG
Key Words: Area, Perimeter, Length,
Width
Starter Activity
Complete the table provided
by drawing a picture of each
polygon and writing in the
formula for finding the area.
10-Apr-15
Level
3
4
5
6
7
8
Shape
Space
Measure
I understand
and can
explain the
difference
between
area and
perimeter.
I can find the
area and
perimeter of
shapes by
counting
squares.
I can find the
area of
rectangles and
squares using a
formula.
I can find the area of
triangles, kites,
parallelogram
trapeziums and circles.
I can use formulae for
the volume of cuboids.
I can find the volume
and surface area of
cuboids.
I can calculate
volumes and
surface area of
prisms and
cylinders.
I understand
the difference
between
formulae for
area,
perimeter and
volume by
considering
dimensions.
I am starting the lesson on level _____________________
By the end of this lesson I want to be able to _____________________
Key Words
Polygon
Length
Width
Height
Perimeter
Area
Surface Area
Volume
Circumference
Radius
Diameter
Pi
Polygon
Name
Formula for Area
Rectangle
Area =
Triangle
Area =
Parallelogram
Area =
Kite
Area =
Trapezium
Area =
Polygon
Name
Formula for Area
Rectangle
Area =
Triangle
Area =
Parallelogram
Area =
Kite
Area =
Trapezium
Area =
Polygon
Name
Formula for Area
Rectangle
Area = length x width
Triangle
Area = (base x height) ÷ 2
Parallelogram
Area = base x perpendicular height
Rhombus
Area = ½ base x height
Trapezium
Area = ½ (sum of parallel sides) x height
4cm
5cm
So area of a parallelogram is ;
Base x perpendicular height
= 20cm2
8cm
8cm
Height hasn’t changed –
still 8cm
Width has halved
to 3cm.
6cm
3cm
So – area of a kite or rhombus is;
Half of base x height
=3x8
= 24cm2
Now for the tricky one;
1cm
6cm
1cm
4cm
1cm
1cm
10cm
Now for the tricky one;
6cm
4cm
The width of the rectangle is the
same as the height of the
trapezium.
The length of the rectangle is the
same as the bottom and top of
the trapezium added together and
then halved.
10cm
So – area of a Trapezium is;
Half the sum of the parallel sides x the
gap between them.
= (6+10)/2 x 4
= 32cm2
Today’s Task
•Work out the area of each polygon, you
will need to measure the sides.
•Fit them together to create a house
•Find the total area of the house.