Question

Please solve the following Geometry problem...

Answer 1

I don't know I also want this answer only in geometry

Answer 2

Answer:

see below

Step-by-step explanation:

theorem : angles opposite to equal sides are equal in a triangle

in ∆ ABC , AB =AC ( Equal sides)

^B = ^C = x (equal angles)

now...

in ∆ADC...AD = AC

hence...^C = ^D = y

but ^CAD =x + x = 2x (ext angle theorem)

so...in ∆ADC...

2x + y + y = 180° ( angle sum property)

2x + 2y = 180°

x + y = 90°

hence ^BCD = x + y = 90°