Triangle ABC , BC = CD and (angle ABC - angle bac ) =30, the measure of angle and is?

Ans is 15°

where does D come in with a triangle?

and what does

measure of angle and is mean?

If H is the circumcenter of BCD find each missing measure

To find the measure of angle BAC, we'll use the fact that the sum of the angles in a triangle is always 180 degrees.

Let's break down the information given:

- The sides BC and CD are equal, implying that triangle BCD is an isosceles triangle, with BC = CD.

- The difference between angle ABC and angle BAC is 30 degrees.

Now, we can proceed with solving the problem:

1. Since BC = CD, triangle BCD is isosceles. This means that angle BCD is equal to angle BDC.

2. Since the sum of the angles in a triangle is 180 degrees, we know that:

angle BAC + angle ABC + angle BCA = 180

3. Also, given that:

angle ABC - angle BAC = 30

4. We can substitute the value of angle ABC in the equation:

angle BAC + (angle BAC + 30) + angle BCA = 180

5. Combine like terms:

2 * angle BAC + angle BCA + 30 = 180

6. Simplify:

2 * angle BAC + angle BCA = 150

7. Now, let's consider triangle BAC. Angles BAC and BCA are both angles in this triangle. So:

angle BAC + angle BCA + angle ABC = 180

8. If we substitute angle ABC with angle BAC + 30 (from step 7), we get:

angle BAC + angle BCA + (angle BAC + 30) = 180

9. Combine like terms:

2 * angle BAC + angle BCA + 30 = 180

10. We can now equate this equation to the equation we derived in step 6:

2 * angle BAC + angle BCA = 2 * angle BAC + angle BCA + 30

11. Simplify:

0 = 30

12. Oops! It appears that there is no solution to this problem.

Therefore, based on the given information, we cannot determine the measure of angle BAC.