Practice 1
Using the words the you have learned,describe the following mathematical symbol.
1) The plus symbol.
2) The minus symbol.
3) The multiplication symbol.
4) The equals symbol.
5) The pi symbol.
Section 2 Angles
Look at the figure and say which
lines are :
1) These two lines meet at an angle. This
angle is less than 90o (ninety degrees).
It is an acute angle.
A
They form a right angle. The two
lines are perpendicular to each other.
5. Lines FK and AB intersect at
point X.The angles FXB and
BXK are next to each other, or
adjacent . The sum of these angles
is 180o. They are supplementary
angles.
6) Angles ABY and YBC are equal.
Line BY bisectes angle ABC.
BY is the bisector of angle ABC.
The sum of angles ABY and YBC is
90o. They are complementary angles.
Practice 3
A
P
S T
B
o
O
M N
Describe the lines and angles in the following figures.
1) 2)
A B C
K
F
x y z
4) 3)
P
P
Z
Unit 8
The triangle
Section 1
A triangel is a three-sided figure. The three sides of a triangel meet at points called
vertices (singular vertex). The vertex at the top a triangle may be called the apex, and
the line at the botton may be called the base.
1) In triangle ABC, line BC is produced to point X. ACB is an interior angle, and
ACX is an exterior angle.
2) This is an isosceles triangle. 3) This is an equilateral triangle. A
B
C
4) This is a right angled triangle.In a
right angled triangle the side
opposite the right angle is called the
hypotenuse.
The theorem of Phytagoras states :
“In a right angled triangle square on
line hypotenuse equal to the sum of
Section 2 Congruence, similarity
And symmetry
1) If the following parts of two
triangles are equal :
a) Two sides and the included
angle ; or,
b) A right angle, hypotenuse and
side ;or,
c) Two angles and a
corresponding side ; or,
d) All three sides ;
Then the two triangles are
conruent.
2) If two triangles have their
corresponding angles equal, they
are similar.
3) These two triangles are on
either side of an exis of
Practice 1
Describe each triangle, and use your ruler to discover any relation ships between the
triangles (i.e.symetry, similarity or congruence).
Vocabulary practice
1) If each of the angles in a triangle is equal to 60o , the triangle is called _________
2) A line which meets another _____________at 90o is called a ____________ line.
3) If two angles of a triangle are equal to 45o , the triangle is called a
_______________________________triangle.
4) If we ______________ a right angle, we have two _____________angles of 45o .
5) Each triangle has three point, or _____________________
1) 2) 3)
4) 5) 6)
7)
