Question

With steps , please .

Answer 1

Θ=15

Explanation:

AD=DC so triangle BCD is isosceles, so angle DBC = angle BCD = Θ

So angle BDC=180-Θ-Θ=180-2Θ

angle BDE = 180- angle BDC = 180-180+2Θ=2Θ

in triangle BDE all angles must add up to 180

angle BED= 180- angle BEA=180-90=90

so

90+4Θ+2Θ=180

90=6Θ

Θ=15