Question

Prove ab+bc+cd+da>ac+bd

Answer 1

Answer:

ab+BC+cd+Da >ac+be

a square c square d square while ac+be they had not any square variable

Answer 2

Step-by-step explanation:

in triangle ABC,

AB+BC >AC eq.(1)[sum of any two sides is greater than the third side]

in triangle BCD,

BC+CD>BD eq.(2)

in triangle ABD,

AB+AD>BD eq.(3)

in triangle ADC,

AD+CD>AC eq.(4)

Adding equation (1),(2),(3)and(4) we get:

2AB+2BC+2CD+2AD>2BD+2AC

2(AB+BC+CD+AD)>2(AC+BD)

AB+BC+CD+AD>AC+BD

hence proved