Question

prove that sum of all angles of a quadrilateral is 360 degree​

Answer 1

Step-by-step explanation:

given:abcd is a quadrilateral

to prove angle a+b+c+d=360°

proof

from∆abc

by the angle sum property

angle cab+abc+acb=180°

similarly,

from ∆adc

angle bac+acd+adc=180°

by adding equations 1 and 2 we get

angle a+b+c+d=360°