# Mathletics grade 10 Perimeter and Area

Introduction

Involve learners into the lesson by asking them what about measuring 2D shapes

Show them an object and ask

• When looking at the edges what do we call it in maths
• Referring to the sides of the object when measuring it what do we call

I will explain to the learners the topic

Perimeter and Area

I will test whether they are eager to learn new things.

Hand out 2D shapes and ask learners if they remember or recall the formula to calculate perimeter and Area

After I will play two videos

Process

After playing the videos I will explain what perimeter and Area is. By doing two examples.

Perimeter just means the distance around a shape, but what does distances mean it is 1 demensional quantity that is measured in cm or m

Example: how do you calculate by adding the edges together.

Determine the perimeter of a triangle  that is measured 5cm by 8cm and 9cm

5 + 8 + 9=22cm (always remember to write the units)

Area is a measure of how much space there is in 2D shapes.

Example: when calculating area you multiply. Lenght × width (L × W). When multiplying the units add (1cm × 1cm=1cm²) meaning your answer will be centimeters squared

Determine the area of a rectangle that is measured 5cm by 8cm

5cm × 8cm = 40cm²

Evaluation

On google classroom I will post a activity for the learners to complete.

Evaluating the learners answer of the activity. I will than know how long I will focus on the topic. Making sure every learner understand how to do calculations and fully understand the formula.

Memo of activity

a. Width of wall = 360cm
Width of tile = 15cm
Number of tiles needed= 360 ÷ 15 = 24
b.  Height of wall is 240cm
Height of tile is 20cm
Number of rows of tiles needed=             240 ÷ 20 = 12
c. Number of tiles needed altogether is       24 × 12 = 288 tiles

1. Area= 8m × 8m = 64m
2. Area= 8cm × 5cm =40cm
3. Area= 4.5cm × 8.5cm = 38.25cm

Picture 1.
Lenght of missing horizontal side= 4m - 1m - 2m = 1m
Perimeter = 1m + 0.5m + 1m + 0.5m + 2m + 3m + 4m + 3m = 15m

Picture 2.
Lenght of missing vertical side= 8m - 2m = 6m
Lenght of missing horizontal side= 12m - 7m = 5m
Perimeter = 12m + 6m + 5m + 2m + 7m + 8m = 40m

Conclusion

Learners revise finding the perimeter and area of a plan (2D) shapes. The activity is largely a reinforcement of what learners already know.

Credits

Learner you can visit the follow side.

https://mathantics.com/

To view more videos.

Teacher Page

Dear learners

I believe this was a exciting activity. However if there is anything that is unclear or that you don't understand, please make use of the WhatsApp group to ask question you can even communicate on google classroom.