Final answer:
To find ACB, subtract the given angle from 180 degrees.
Step-by-step explanation:
To find ACB, we need to use the fact that the sum of angles in a triangle is 180 degrees. Since ADB is given as 15 degrees, we can find ACB by subtracting ADB from 180 degrees. So, ACB = 180 - 15 = 165 degrees.
ACB is based on the angle ADB being 15°. In geometry, unless additional information is provided such as whether the figure is a specific type of triangle (like an isosceles or equilateral triangle), or there are other known angles or relationships, we cannot determine the measure of angle ACB solely based on the measure of angle ADB.
Generally, if you are asked to find the measure of one angle based on another, you would use properties of triangles or the given geometric figure. For example, if the triangle is isosceles with AB as the base, and angles ADB and ACB are the angles at the base, they would be equal. If the triangle is a right triangle and angle ADB is given, and you knew it was part of the 90° angle, you could subtract angle ADB from 90° to find ACB. Without such information, we cannot arrive at a numerical answer for ACB.