Page 203 - Start Up Mathematics_7

Some NCERT Textbook Questions

1. If ∆ABC ≅ ∆FED under the correspondence ABC ↔ FED, write all the corresponding
congruent parts of the triangles.

2. If ∆DEF ≅ ∆BCA, write the part(s) of ∆BCA that correspond to
(i) ∠E (ii) EF (iii) ∠F (iv) DF

3. Which congruence criterion do you use in the following?
(a) Given: AC = DF A D

AB = DE
BC = EF
So, ∆ABC ≅ ∆DEF
B C E F

(b) Given: ZX = RP R Z

RQ = ZY
∠PRQ = ∠XZY
So, ∆PQR ≅ ∆XYZ
P Q X Y

L N
(c) Given: ∠MLN = ∠FGH H
∠NML = ∠GFH

ML = FG
So, ∆LMN ≅ ∆GFH F
M G

D
(d) Given: EB = DB E
AE = BC
∠A = ∠C = 90°

So, ∆ABE ≅ ∆CDB A B C

4. You want to show that ∆ART ≅ ∆PEN. A

(a) If you have to use SSS criterion, then you need to show
(i) AR = (ii) RT = (iii) AT =

R T

P
(b) If it is given that ∠T = ∠N and you are to use SAS criterion,
you need to have
(i) RT = and (ii) PN =
E N

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