Practical Geometry Class 8 PPT

 Page 1


P r a c t i c a l
G e o m e t r y
Class-8
Page 2


P r a c t i c a l
G e o m e t r y
Class-8
Geometry is a branch of mathematics concerned
with questions of shape, size, relative position of
figures, and the properties of space. The word
geometry came from the Ancient Greek word :
YEWWEtpia (geometron) . Where geo- means
"earth" and -Metron means "measurement".
What is Geometry?
Page 3


P r a c t i c a l
G e o m e t r y
Class-8
Geometry is a branch of mathematics concerned
with questions of shape, size, relative position of
figures, and the properties of space. The word
geometry came from the Ancient Greek word :
YEWWEtpia (geometron) . Where geo- means
"earth" and -Metron means "measurement".
What is Geometry?
We shall learn how to construct a unique
quadrilateral given the following
measurements:
• When four sides and one diagonal are given.
• When two diagonals and three sides are given.
• When two adjacent sides and three angles are
given.
• When three sides and two included angles are
given.
• When other special properties are known.
Quadrilateral
Page 4


P r a c t i c a l
G e o m e t r y
Class-8
Geometry is a branch of mathematics concerned
with questions of shape, size, relative position of
figures, and the properties of space. The word
geometry came from the Ancient Greek word :
YEWWEtpia (geometron) . Where geo- means
"earth" and -Metron means "measurement".
What is Geometry?
We shall learn how to construct a unique
quadrilateral given the following
measurements:
• When four sides and one diagonal are given.
• When two diagonals and three sides are given.
• When two adjacent sides and three angles are
given.
• When three sides and two included angles are
given.
• When other special properties are known.
Quadrilateral
S is 5.5 cm away from point P. To represent this, draw an arc with a radius of 5.5 cm, using
P as the center. (S should lie somewhere on this arc.)
Additionally, S is situated 5 cm away from point R. To illustrate this, draw another arc with
a radius of 5 cm, using R as the center.
Objective: Construct a quadrilateral PQRS with the following measurements: PQ = 4 cm,
QR = 6 cm, RS = 5 cm, PS = 5.5 cm, and PR = 7 cm. Begin by creating a rough sketch of the
quadrilateral.
Step 1: Begin with a rough sketch of the quadrilateral based on the provided measurements.
This sketch will serve as a visual reference.
Step 2: Now, focus on constructing triangle APQR, which is evident from the rough sketch and
can be achieved using the Side-Side-Side (SSS) construction condition. Draw triangle APQR.
Step 3: Next, we need to locate the fourth point, S. Position S on the side opposite to Q
concerning side PR. We have two specific measurements to guide us:
Step 4: The point S should lie on both of the arcs previously drawn. Therefore, S is the
intersection point of these two arcs. Mark this point as S and finalize the construction of
quadrilateral PQRS.
1. When the length of four sides and a diagonal is gives 
Page 5


P r a c t i c a l
G e o m e t r y
Class-8
Geometry is a branch of mathematics concerned
with questions of shape, size, relative position of
figures, and the properties of space. The word
geometry came from the Ancient Greek word :
YEWWEtpia (geometron) . Where geo- means
"earth" and -Metron means "measurement".
What is Geometry?
We shall learn how to construct a unique
quadrilateral given the following
measurements:
• When four sides and one diagonal are given.
• When two diagonals and three sides are given.
• When two adjacent sides and three angles are
given.
• When three sides and two included angles are
given.
• When other special properties are known.
Quadrilateral
S is 5.5 cm away from point P. To represent this, draw an arc with a radius of 5.5 cm, using
P as the center. (S should lie somewhere on this arc.)
Additionally, S is situated 5 cm away from point R. To illustrate this, draw another arc with
a radius of 5 cm, using R as the center.
Objective: Construct a quadrilateral PQRS with the following measurements: PQ = 4 cm,
QR = 6 cm, RS = 5 cm, PS = 5.5 cm, and PR = 7 cm. Begin by creating a rough sketch of the
quadrilateral.
Step 1: Begin with a rough sketch of the quadrilateral based on the provided measurements.
This sketch will serve as a visual reference.
Step 2: Now, focus on constructing triangle APQR, which is evident from the rough sketch and
can be achieved using the Side-Side-Side (SSS) construction condition. Draw triangle APQR.
Step 3: Next, we need to locate the fourth point, S. Position S on the side opposite to Q
concerning side PR. We have two specific measurements to guide us:
Step 4: The point S should lie on both of the arcs previously drawn. Therefore, S is the
intersection point of these two arcs. Mark this point as S and finalize the construction of
quadrilateral PQRS.
1. When the length of four sides and a diagonal is gives 1. When the length of four sides and a diagonal is gives