Page 55 - Mathematics Class - X

OBSERVATIONS
Measure each part as given in the observation table and write its value.

∆ABC ∆PQR ∆XYZ

AD =_____ PL =_____ XU =_____
DB LQ UY

AE =_____ PM XV =_____

EC MR =_____ VZ

AF =_____ PS =_____ XI =_____

FB SQ IY

AG =_____ PT =_____ XJ =_____
GC TR JZ

INFERENCE
(Write Yes/No)

AD AE AF AG PL PM
1. Is = ? Yes 2. Is = ? 3. Is = ?
DB EC FB GC LQ MR

PS PT XU XV XI XJ
4. Is = ? 5. Is = ? 6. Is = ?
SQ TR UY VZ IY JZ

[Note: We may get approximate answer here.]

EXTENDED TASK

1. Verify by activity method that in a triangle, if two or three parallel lines are
drawn parallel to one side, then they divide the other two sides in the same
proportion.
2. Write an article full of pictures and information on Thales, the Greek
Mathematician and his famous five theorems on Geometry.

APPLICATION

1. Basic Proportionality theorem can be used to establish various criteria based upon similarity of triangles.
2. This theorem can also be used for constructing a polygon similar to a given polygon.

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