2. INTRODUCTION
• We know that a closed figure
formed by three intersecting lines
is called a triangle(‘Tri’ means
‘three’).A triangle has three sides,
three angles and three vertices.
For e.g.-in Triangle ABC, denoted
as ΔABC AB,BC,CA are the three
sides, ∠A,∠B,∠C are three angles
and A,B,C are three vertices.
3. Similarity Of
Triangles
• Two geometrical objects are called similar if they
both have the same shape, or one has the same
shape as the mirror image of the other. More
precisely, one can be obtained from the other by
uniformly scaling (enlarging or reducing), possibly
with additional translation, rotation and reflection.
This means that either object can be rescaled,
repositioned, and reflected, so as to coincide
precisely with the other object.
4. Similar Figures
Two figures that have the same shape are said to
be similar. When two figures are similar, the
ratios of the lengths of their corresponding sides
are equal. To determine if the triangles below
are similar, compare their corresponding sides.
5. Area of Similar Triangles
• Similar Triangles: Perimeters and Areas. When
two triangles are similar, the reduced ratio of
any two corresponding sides is called the scale
factor of the similar triangles. In Figure 1 , Δ
ABC∼ Δ DEF. ... It is then said that the scale
factor of these two similar triangles is 2 : 1.
6. Pythagoras Theorem
• In mathematics, the Pythagorean
theorem, also known as Pythagoras's
theorem, is a fundamental relation
in Euclidean geometry among the three
sides of a right triangle. It states that the
square of the hypotenuse (the side
opposite the right angle) is equal to the
sum of the squares of the other two
sides. The theorem can be written as
an equation relating the lengths of the
sides a, b and c, often called the
"Pythagorean equation“.
