Question

Please solve question 3

Answer 1

Answer:

In equilateral triangle DEC

DE=EC ----1

ANGLE CDE= ANGLE DCE (angles opposite to equal sides of a triangle are equal) -----2

In square ABCD

AD=BC(all sides of a square are equal) -----3

ANGLE ADC= ANGLE BCD (90 degree each) ----4

Adding 2 and 4

ANGLE CDE + ANGLE ADC= ANGLE DCE+ ANGLE BCD

ANGLE ADE= ANGLE BCE -----5

In triangle ADE and BCE

AD=BC (from 3)

DE=EC (from 1)

ANGLE ADE= ANGLE BCE ( from 5)

By SAS congruence rule triangle ADE and BCE  are congruent.