The chords of the circle AC and BD intersect. Find the CAD angle if ABD = 30 degrees and ADC = 50 degrees.

Internal angle ABD is based on the chord AD, the degree of which is equal to two internal angles.

Arc AD = 2 * 30 = 60.

The internal angle ACD also rests on the arc AD, therefore, its size is equal to half the degree measure of the arc AD.

Angle АСD = АD / 2 = 60/2 = 30 cm.

Consider a triangle ACD, for which two interior angles are known, then:

Angle CAD = 180 – ADC – ACD = 180 – 50 – 30 = 100.

Answer: The value of the CAD angle is 100.



One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.