на рисунке bd=dc bc||de, угол BDE=40°. Найдите угол ADE

To find angle ADE, we need to use the property that the sum of the angles in a triangle is 180 degrees.

Since BC is parallel to DE, angle BDC and angle EDC are equal. Therefore, angle BDE and angle EDC add up to 180 - angle BDC.

Given that angle BDE is 40 degrees, we can conclude that angle EDC is also 40 degrees.

Now let's consider triangle ADE. We have:

angle ADE + angle EDA + angle EAD = 180 degrees

angle ADE + 40 + 90 = 180

angle ADE + 130 = 180

angle ADE = 180 - 130

angle ADE = 50 degrees.

Therefore, angle ADE is equal to 50 degrees.