Congruence of Triangles Ex-7.1

NCERT solutions for Maths Congruence of Triangles

NCERT Solutions for Class 7 Maths Congruence of Triangles

Class –VII Mathematics (Ex. 7.1)

Question 1.Complete the following statements:

1. Two line segments are congruent if _______________.
2. Among two congruent angles, one has a measure of $70^\circ ,$ the measure of other angle is _______________.
3. When we write $\angle$A = $\angle$B, we actually mean _______________.

Answer:

(a) they have the same length

(b) $70^\circ$

(c) $m\angle$A = $m\angle$B

Question 2.Give any two real time examples for congruent shapes.

Answer:

(i) Two footballs

(ii) Two teacher’s tables

NCERT Solutions for Class 7 Maths Exercise 7.1

Question 3.If $\Delta$ABC $\cong \Delta$FED under the correspondence ABC $\leftrightarrow$ FED, write all the corresponding congruent parts of the triangles.

Answer:

Given: $\Delta$ABC $\cong$$\Delta$FED.

The corresponding congruent parts of the triangles are:

(i) $\angle$A $\leftrightarrow$$\angle$F

(ii) $\angle$B $\leftrightarrow$$\angle$E

(iii) $\angle$C $\leftrightarrow$$\angle$D

(iv) $\overline {{\text{AB}}}$$\leftrightarrow$$\overline {{\text{FE}}}$

(v) $\overline {{\text{BC}}}$$\leftrightarrow$$\overline {{\text{ED}}}$

(vi) $\overline {{\text{AC}}}$$\leftrightarrow$$\overline {{\text{FD}}}$

NCERT Solutions for Class 7 Maths Exercise 7.1

Question 4.If $\Delta$DEF $\cong \Delta$BCA, write the part(s) of $\Delta$BCA that correspond to:

i.$\angle$E

ii.$\overline {{\text{EF}}}$

iii.$\angle$F

iv.$\overline {{\text{DF}}}$

Answer:

Given: $\Delta$DEF $\cong$$\Delta$BCA.

(i) $\angle$E $\leftrightarrow$$\angle$C

(ii) $\overline {{\text{EF}}}$$\leftrightarrow$$\overline {{\text{CA}}}$

(iii) $\angle$F $\leftrightarrow$$\angle$A

(iv) $\overline {{\text{DF}}}$$\leftrightarrow$$\overline {{\text{BA}}}$