Better?• In this case, the light bulb is the centre of enlargement!• C. of E. is the point from which the E. is constructed.
The Scale Factor• Is denoted by the Let’s see it in action! letter ‘k’ in the new course.• It is the number by which the object is fun enlargements enlarged. http://www.ngﬂ-cymru.org.uk/vtc/ngﬂ/maths/echalk/enlargement/intro/enlargementIntro.html
In Action http://www.ngﬂ-cymru.org.uk/vtc/ngﬂ/maths/echalk/enlargement/intro/enlargementIntro.html
• Important to note that while enlargements normally enlarge shapes you can also decrease, reduce or make shapes smaller.• For example if k = 1/2 then your shape would be half the original size!
Properties of enlargements • Shape of image is the same only size has changed. • Angle measures remain the same. • Image length = k (object length) OR • k = Image length/Object length • Area of Image = k^2 (area object) OR • k^2 = Area of Image/Area of object
• 1. Choose two points on the image and their corresponding points on the original ﬁgure.• 2. From each of these points on the larger ﬁgure, draw a line to the corresponding point on the smaller ﬁgure.• 3. Produce these lines until they intersect at the point is the centre of the enlargement.