Question

Please solve this sum

Answer 1

Step One

Find <ACB

Since AB = BC the triangle ABC is isosceles. That means that the angles opposite the equal sides are equal.

Therefore <ACB = <CAB = <40o

Step Two

find angle ABC

ABC + BAC + BCA = 180o        All Triangles have 180o

<ABC + 40o + 40o =  180o

<ABC + 80o = 180o

<ABC = 180o - 80o

<ABC = 100o

Step three

Find <ADC

In a cyclic Quadrilateral The angles opposite each other are Supplementary. So because <ABC and <ADC are oppose each other they will equal 180o.

<ABC + <ADC = 180o

100o + <ADC = 180o

<ADC = 180o - 100o

<ADC = 80o

Step Four

Find <ADE

<ADC +< ADE = 180o

<ADE + 80o = 180o

<ADE = 100o