Final answer:
To find the measure of the unknown angle in a straight angle ABC, you can use the equation A = A + A. This equation is derived from the Pythagorean theorem, which relates the legs of a right triangle to the length of the hypotenuse.
Step-by-step explanation:
To find the measure of the unknown angle in a straight angle ABC, you can use the equation A = A + A. This equation is derived from the Pythagorean theorem, which relates the legs of a right triangle to the length of the hypotenuse. In a straight angle, the two legs are equal, so the equation simplifies to A = 2A. Therefore, the measure of the unknown angle is twice the measure of one of the legs