Question

Find the value of x. use very easy method xD​

Answer 1

In triangle ABC,

Angle A+Angle B+Angle C=180°

(Angle sum property of triangle)

40°+Angle B+90°=180°

Angle B+130°=180°

Angle B=180°-130°=50°... (i)

Now, in Triangle BDE

Angle B+Angle D+Angle E=180°

(Angle sum property of Triangle)

50°+Angle D+100°=180°(Angle B=50°... from (i)

150°+Angle D=180°

Angle D=180°-150°=30°

Hence, x=30°