Similar+Triangles+Part+I

Here is a similar triangles rap to view as a class. media type="youtube" key="628eYW4O8hM?rel=0" height="360" width="480" align="center"
 * __Similar Triangles Part I __**

Work through these questions to discover some of the key properties of similar triangles. 1. The diagrams show two equilateral triangles.  a) Are the ratios of the matching sides equal? b) Are the triangles similar? 2. The three purple triangles shown are drawn on a grid of parallel lines.  a) Look at triangles ABC and DEF: (i) Are the matching angles equal?  (ii) Name the sides in triangle DEF that match the sides AB, BC and AC.  (iii) Are the ratios of matching sides equal?   b) Look at triangles GHI and DEF:  (i) Name the pairs of matching angles. Are the matching angles equal? (ii) What is the value of each of the ratios DE:GH, EF:HI and DF:IG? <span style="color: #008000; font-family: 'Comic Sans MS',cursive; font-size: 150%;">(iii) Are the triangles similar? <span style="color: #000080; font-family: 'Comic Sans MS',cursive; font-size: 150%;">3. The triangles shown have their matching angles equal. <span style="font-family: 'Comic Sans MS',cursive; font-size: 150%;"> <span style="color: #000080; font-family: 'Comic Sans MS',cursive; font-size: 150%;">The lengths of the sides have been measured and to the nearest millimetre and recorded in the table. <span style="color: #000080; font-family: 'Comic Sans MS',cursive; font-size: 150%;">Use the results in the table to calculate the value of the ratio of each pair of matching sides correct to one decimal place. <span style="background-color: #ff0000; font-family: 'Comic Sans MS',cursive; font-size: 200%;">Two triangles are similar if matching angles are equal. <span style="background-color: #ff0000; font-family: 'Comic Sans MS',cursive; font-size: 200%;">This means that the ratios of matching sides are equal. <span style="color: #008000; font-family: 'Comic Sans MS',cursive; font-size: 150%;">4. Identify the triangles that are similar in each of the following questions. <span style="font-family: 'Comic Sans MS',cursive; font-size: 150%; line-height: 0px; overflow-x: hidden; overflow-y: hidden;">
 * Side || AB || BC || AC || DE || EF || DF ||
 * Length || 26 || 30 || 20 || 47 || 54 || 35 ||

<span style="font-family: 'Comic Sans MS',cursive; font-size: 20px;">

<span style="color: #000080; font-family: 'Comic Sans MS',cursive; font-size: 20px;">5. Each of the triangles A to J is similar to one of the triangles L to W. Match the triangles that are similar. <span style="font-family: 'Comic Sans MS',cursive; font-size: 20px;">
 * __<span style="font-family: 'Comic Sans MS',cursive; font-size: 20px; line-height: 0px; overflow-x: hidden; overflow-y: hidden;">﻿ __**<span style="font-family: 'Comic Sans MS',cursive; font-size: 20px;">[[image:urallamaths/10026.JPG]]

<span style="font-family: 'Comic Sans MS',cursive; font-size: 20px;">﻿Now try this activity from the Tale4Students site by entering the save code X02P6 on the right. <span style="font-family: 'Comic Sans MS',cursive; font-size: 20px;">Tale4Students <span style="font-family: 'Comic Sans MS',cursive; font-size: 20px;">Here is an extension question for fast finishers. <span style="color: #008000; font-family: 'Comic Sans MS',cursive; font-size: 20px;">6. The diagrams show two right-angled triangles with their matching sides equal. <span style="font-family: 'Comic Sans MS',cursive; font-size: 20px;">  <span style="font-family: 'Comic Sans MS',cursive; font-size: 20px;">a) Find the values of <span style="font-family: 'Comic Sans MS',cursive;">// x // and //y// by calculation.    <span style="color: #008000; font-family: 'Comic Sans MS',cursive; font-size: 20px;">b) Calculate the ratios of the matching sides. Are they equal? <span style="color: #008000; font-family: 'Comic Sans MS',cursive; font-size: 20px;">c) Are the triangles similar?