MTH 4-16a 1-Aug-15Compiled by Mr. Lafferty Maths Dept. Pythagoras Theorem Squaring a Number and Square Roots Investigating Pythagoras Theorem Finding the length of the smaller side Calculating the Hypotenuse Solving real-life problems Distance between two points & Mixed Problems

MTH 4-16a 1-Aug-15Compiled by Mr. Lafferty Maths Dept. Starter Questions

MTH 4-16a 1-Aug-15Compiled by Mr. Lafferty Maths Dept. Squaring a Number Learning Intention Success Criteria 1.To understand what is meant by the term ‘squaring a number’ 1.We are learning the term ‘squaring a number’. 2.Be able to calculate squares both mentally and using the calculator.

MTH 4-16a 1-Aug-15Compiled by Mr. Lafferty Maths Dept. Squaring a Number To square a number means to : “Multiply it by itself” means 9 x 9 = 81 Example : means 10 x 10 = 100

MTH 4-16a 1-Aug-15Compiled by Mr. Lafferty Maths Dept. Now try Exercise 1 Ch59 (page 202) Squaring a Number

MTH 4-16a 1-Aug-15Compiled by Mr. Lafferty Maths Dept. Square Root of a number You now know how to find : We can ‘undo’ this by asking “which number, times itself, gives 81” 9 2 = 9 x 9 = 81 From the top line, the answer is 9 This is expressed as : “ ““ “the SQUARE ROOT of 81 is 9” or in symbols we write :

MTH 4-16a 1-Aug-15Compiled by Mr. Lafferty Maths Dept. Now try Exercise 2 Ch59 (page 203) Square Root of a Number

1-Aug-15 Compiled by Mr. Lafferty Maths Dept. Starter Questions Q1.Are the missing angles 65 o, 40 o and 65 o Q2.Calculate Q3. The cost of a new computer is £1000 +vat. If the vat is charged at 12% what is the total cost. Q4. The cost of a bag of sugar is £1.12. How much 50 bags cost. 115 o NON-CALCULATOR MTH 4-16a

1-Aug-15 Compiled by Mr. Lafferty Maths Dept. ‘To investigate the right-angle triangle and to come up with a relationship between the lengths of its two shorter sides and the longest side which is called the hypotenuse. ‘ Aim of today's Lesson Right – Angle Triangles MTH 4-16a

1-Aug-15 Compiled by Mr. Lafferty Maths Dept. Right – Angle Triangles What is the length of a ? What is the length of b ? Copy the triangle into your jotter and measure the length of c MTH 4-16a

1-Aug-15 Compiled by Mr. Lafferty Maths Dept. Right – Angle Triangles What is the length of a ? What is the length of b ? Copy the triangle into your jotter and measure the length of c

1-Aug-15 Compiled by Mr. Lafferty Maths Dept. Right – Angle Triangles What is the length of a ? What is the length of b ? Copy the triangle into your jotter and measure the length of c MTH 4-16a

1-Aug-15 Compiled by Mr. Lafferty Maths Dept. Right – Angle Triangles abca2a2 b2b2 c2c Copy the table below and fill in the values that are missing MTH 4-16a

1-Aug-15 Compiled by Mr. Lafferty Maths Dept. Right – Angle Triangles abca2a2 b2b2 c2c Can anyone spot a relationship between a 2, b 2, c 2. MTH 4-16a

1-Aug-15 Compiled by Mr. Lafferty Maths Dept. Pythagoras’s Theorem a b c MTH 4-16a

1-Aug-15 Compiled by Mr. Lafferty Maths Dept. Summary of Pythagoras’s Theorem Note: The equation is ONLY valid for right-angled triangles. MTH 4-16a

1-Aug-15Compiled by Mr. Lafferty Maths Dept. Now try Exercise 3 59(page 204) Pythagoras Theorem

MTH 4-16a 1-Aug-15Compiled by Mr. Lafferty Maths Dept. Starter Questions

MTH 4-16a 1-Aug-15Compiled by Mr. Lafferty Maths Dept. Calculating Hypotenuse Learning IntentionSuccess Criteria 1.Remember the term hypotenuse “ the longest side” 1.We are learning to use Pythagoras Theorem to calculate the length of the hypotenuse “the longest side” 2.Apply Pythagoras Theorem to calculate the hypotenuse.

1-Aug-15 Compiled by Mr. Lafferty Maths Dept. Calculating the Hypotenuse 8 12 c Calculate the longest length of the right- angled triangle below. Example 1 MTH 4-16a

1-Aug-15 Compiled by Mr. Lafferty Maths Dept. Calculating the Hypotenuse Aeroplane b = 8 a = 15 c Lennoxtown Airport An aeroplane is preparing to land at Glasgow Airport. It is over Lennoxtown at present which is 15km from the airport. It is at a height of 8km. How far away is the plane from the airport? Example 2 MTH 4-16a

1-Aug-15Compiled by Mr. Lafferty Maths Dept. Now try Exercise 4 Ch59 (page 205) Calculating Hypotenuse

MTH 4-16a 1-Aug-15Compiled by Mr. Lafferty Maths Dept. Starter Questions

MTH 4-16a 1-Aug-15Compiled by Mr. Lafferty Maths Dept. Solving Real-Life Problems Learning Intention Success Criteria 1.Be able to solve real-life problems using Pythagoras Theorem showing clear working. 1.We are learning how Pythagoras Theorem can be used to solve real-life problems.

MTH 4-16a 1-Aug-15Compiled by Mr. Lafferty Maths Dept. Solving Real-Life Problems Example :A steel rod is used to support a tree which is in danger of falling down. What is the length of the rod? When coming across a problem involving finding a missing side in a right-angled triangle, you should consider using Pythagoras’ Theorem to calculate its length. 15m 8m rod

MTH 4-16a 1-Aug-15Compiled by Mr. Lafferty Maths Dept. Solving Real-Life Problems Example 2 A garden is rectangular in shape. A fence is to be put along the diagonal as shown below. What is the length of the fence. 10m 15m

MTH 4-16a 1-Aug-15Compiled by Mr. Lafferty Maths Dept. Now try Exercise 5 Ch59 (page 208) Solving Real-Life Problems

MTH 4-16a 1-Aug-15Compiled by Mr. Lafferty Maths Dept. Starter Questions

MTH 4-16a 1-Aug-15Compiled by Mr. Lafferty Maths Dept. Length of the smaller side Learning Intention Success Criteria 1.Apply Pythagoras Theorem to find the length of smaller side showing clear working. 1.We are learning how Pythagoras Theorem can be used to find the length of the smaller side.

MTH 4-16a 1-Aug-15Compiled by Mr. Lafferty Maths Dept. Length of the smaller side Example :Find the length of side a ? To find the length of the smaller side of a right- angled triangle we simply rearrange Pythagoras Theorem. 20cm 12cm a cm Check answer ! Always smaller than hypotenuse

MTH 4-16a 1-Aug-15Compiled by Mr. Lafferty Maths Dept. Length of the smaller side Example :Find the length of side b ? 10cm b cm 8 cm Check answer ! Always smaller than hypotenuse

MTH 4-16a 1-Aug-15Compiled by Mr. Lafferty Maths Dept. Now try Exercise 6 Ch59 (page 211) Length of smaller side

MTH 4-16a Starter Questions ALWAYS comes up in exam !!

MTH 4-16a 1-Aug-15Compiled by Mr. Lafferty Maths Dept. Learning Intention Success Criteria 1.Apply Pythagoras Theorem to find length of a line. 1. We are learning how Pythagoras Theorem can be used to find the length of a line. 2.Show all working. Finding the Finding the Length of a Line

MTH 4-16a 1-Aug-15 Created by Mr. Lafferty Maths Dept (7,7) (2,4) 3 5 Finding the Length of a Line Discuss with your partner how we might find the length of the line.

1-Aug-15 Created by Mr. Lafferty Maths Dept (9,1) (0,6) 5 9 Pythagoras Theorem to find the length of a Line MTH 4-16a

1-Aug-15Compiled by Mr. Lafferty Maths Dept. Pythagoras Theorem Finding hypotenuse c Finding shorter side a Finding shorter side b a c b

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MTH 4-16a 1-Aug-15Compiled by Mr. Lafferty Maths Dept. Now try Exercise 7 Ch59 (page 213) Pythagoras Theorem