Question

ch-10 abcd is a cyclic quadrilateral . if AC bisects both the angles A and C , then prove that angle ABC =90 °​

Answer 1

Step-by-step explanation:

In the triangles ABC & ADC

∠BAC=∠DAC

∠DCA=∠BCA

AC=CA

ΔABC & ΔADC are congruent

∠CDA=∠ABC

∠CDA+∠ABC=180° (opposite angle of a cyclic quadrilateral are supplementary)

2ABC=180°

∠ABC=180/2

∠ABC=90°