Manipulating Formulas for Geometric Shapes
How to calculate unknown values by manipulating formulas for shapes like squares, rectangles, triangles, circles, and semi-circles when the perimeter/circumference and area are given. Follow step-by-step examples to practice the concept.
Download Presentation

Please find below an Image/Link to download the presentation.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author. Download presentation by click this link. If you encounter any issues during the download, it is possible that the publisher has removed the file from their server.
E N D
Presentation Transcript
L3 MATHS LITERACY TOPIC 2 LESSON 1 SPACE AND SHAPE MANIPULATION OF FORMULAE SUBJECT OUTCOME/S: (this is what you need to understand and apply) 2.2.5 Manipulate given formulae to calculate the unknown values when the perimeter/circumference and area of the following shapes are given: Square Rectangle Triangle Circle Semi-circle compiled by B Adams 1
In order for us to understand the above outcome, we must first make sure that we know our formulas. In L2 you were expected to just work out the perimeter, area or volume. But for L3, we give you the worked out perimeter, area or volume. You then need to find the missing dimension (length, breath, height, radius etc.) This means that when we have our formula (Halleluja) we can substitute the values that they have given us into the formula. Look at the examples on the following slides: compiled by B Adams 2
LETSLOOKATSOMEEXAMPLES: Example 1: The area of a rectangular room is ????. The length of the one side is 6m. What is the breath? Step 1 What did the question ask? Step 2 What shape do you see/or did the question mentioned? Step 3 Is the dimensions in the same unit (meters, centimeters or millimeters) Step 4 What is the related formula (look at step 1 and 2) Step 5 Write the formula down and substitute what was given in the Question. compiled by B Adams Area = 30?2 Length 6m 1. Work out the breath 2. A rectangle was mentioned in the question (if you are unsure draw the shape for yourself) 3. The dimensions are in the same unit - meters 4. ???? ?? ? ????????? = ???? ? ????? 5. Substitute what was given in the question 30?2= 6m ????? 30?2 5? = ????? 6? =6m ????? (divide both sides by 6m) 3 6?
CONTINUE: EXAMPLE 2 The Volume of a cylinder is 282,6??3. Calculate the radius of the cylinder if the height is 10cm. Step 1 What did the question ask? Step 2 What shape do you see/or did the question mentioned? Step 3 Is the dimensions in the same unit (meters, centimeters or millimeters) Step 4 What is the related formula (look at step 1 and 2) Step 5 Write the formula down and substitute what was given in the Question. compiled by B Adams Volume = 282,6??3 Height 10cm 1. 2. 3. 4. 5. Work out the radius A cylinder Dimensions is the same in centimeters ?????? ?? ??linder = ?2 Substitute into the formula: ?????? ?? ??linder = ?2 282,6??3= 3,14 ?2 10?? (You are allowed to swapped both sides of the equal = sign) 3,14 ?2 10?? = 282,6??3 31,4?? ?2 = 282,6??3 (divide both sides with 31,4cm) ?2= 9??2 ?2= 9??2 ? = 3?? 4
LETSDOAFEWNOWTOPRACTICE: Go to page 124 Exercise 2.6 Do the following Questions 1, 2,3,4 and 5 compiled by B Adams Please use the steps as given above for each question. After substitution you need to work out the answer. You can do this guys. If there were NO picture with the question draw it, visualise it for yourself and write the dimensions in. 5 Good luck and shout if you are stuck!