If the measure of ABC = 180o, and the length of AD and DC are equal, which is the measure of ACD?

If the measure of ABC is 180 degrees, it indicates that ABC is a straight line. In a straight line, the sum of the angles is 180 degrees.

Since AD and DC are equal in length, triangle ACD is an isosceles triangle. In an isosceles triangle, the base angles are equal.

Therefore, the measure of angle ACD is 180 degrees - (angle ABC/2).

In order to find the measure of ACD, we need to know more information about the triangle ABC. Specifically, we need to know the type of triangle or if any angles are given. Without this information, we cannot determine the measure of ACD.

However, if we assume that triangle ABC is an isosceles triangle, meaning that two sides are equal in length, then we can proceed to find the measure of ACD.

Let's call the length of AD and DC as x units. Since we have an isosceles triangle, we know that angles A and C are congruent.

Now, let's start with the given information that the measure of angle ABC is 180 degrees. In any triangle, the sum of all angles is always 180 degrees. So, we can write the equation:

angle A + angle B + angle C = 180 degrees

Since angle A and angle C are congruent, we can replace angle A with angle C:

angle C + angle B + angle C = 180 degrees

Combining like terms, we get:

2 angle C + angle B = 180 degrees

Now, let's rewrite angle C as ACD:

2 ACD + angle B = 180 degrees

Since we don't know the measure of angle B, we cannot determine the exact measure of ACD without more information. However, we can make a general statement. In an isosceles triangle, the base angles (angles that are opposite the equal sides) are always congruent. Therefore, if angle B is the base angle, then angle C (or ACD) would also be the same measure as angle B.

In summary, without more information about the triangle ABC, we cannot determine the exact measure of ACD. However, if triangle ABC is isosceles and angle B is the base angle, then the measure of ACD would be the same as angle B.