Unit 1 day 6:

Day 6: Angles in similar triangles.
Explanation:http://www.youtube.com/watch?v=s4fr9vC9C5Q&feature=player_embedded#!
Examples:Triangles are similar if they have the same shape, but not necessarily the same size. You can think of it as "zooming in" or out making the triangle bigger or smaller, but keeping its basic shape. In the figure above, as you drag any vertex on triangle PQR, the other triangle changes to be the same shape, but half the size. In formal notation we can write

which is read as "Triangle PQR is similar to triangle P'Q'R' ".

Quiz:

Key:

1)D

2)D

3)B

1

Marks: --/1

Determine which of the following triangles are similar.

Choose one answer.

	a.
	b.
	c.
	d.

Question2

Marks: --/1

The minimum condition for the similarity of two triangle is that

Choose one answer.

	a. any one angle must be equal and two corresponding sides must be in the same proportion.
	b. at least two corresponding sides must be in the same proportion.
	c. all three corresponding angles must be equal.
	d. at least two corresponding angles must be equal.

Question3

Marks: --/1

Similar triangles always have

Choose one answer.

	a. the same perimeter.
	b. the same shape.
	c. the same area.
	d. all of these.