Question

1 ) in the given figure if AE=7 cm and AB=BC=25cm and CD=
24 cm find the length of DE
​

Answer 1

Step-by-step explanation:

Given: AB∥CD

Construction: Draw a perpendicular on CD from B, meting CD at E

Thus, BE = AD

Now, In △ABD,

BD

2

=AD

2

+AB

2

25

2

=AD

2

+7

2

AD=24 cm

thus, BE=AD=24 cm

and CE=CD−AB=17−7=10 cm

Now, In △BCE BC2

=BE 2+CE 2

BC 2 =24

2+10

2

BC 2=676

BC=26 cm

Answer 2

Answer:

Given: AB∥CD

Construction: Draw a perpendicular on CD from B, meting CD at E

Thus, BE = AD

Now, In △ABD,

BD2=AD2+AB2

252=AD2+72

AD=24 cm

thus, BE=AD=24 cm

and CE=CD−AB=17−7=10 cm

Now, In △BCE

BC2=BE2+CE2

BC2=242+102

BC2=676

BC=26 cm