Given that, m less than A B C equals 80 degree . Find straight m angle ADC

To find the measure of angle ADC, we need to consider the given information:

1. We have a triangle ABC, and the angle ABC measures 80 degrees.
2. We want to find the measure of angle ADC.

To solve this, we can use the fact that the sum of angles in a triangle is always 180 degrees.

Step 1: Find the measure of angle BAC
We know that the sum of the angles in triangle ABC is 180 degrees. Since we are given that angle ABC measures 80 degrees, we can subtract this from 180 to find the measure of angle BAC:
BAC = 180 - ABC
BAC = 180 - 80
BAC = 100 degrees

Step 2: Find the measure of angle ADC
To find the measure of angle ADC, we can use the fact that the angles at a point (sum of angles around a point) is always 360 degrees. In this case, the angles at point D are angle ADC and angle BDC. Since we know the measures of angles BAC and ABC, we can subtract them from 360 to find the measure of angle ADC:
ADC = 360 - (BAC + ABC)
ADC = 360 - (100 + 80)
ADC = 360 - 180
ADC = 180 degrees

Therefore, the measure of angle ADC is 180 degrees.