For the first question, note how the complement of an angle is going to be added to the angle to measure 90 degrees. Therefore, you may represent the first question with the equation "(2x+42)+x=90," since the sum of the two angles would be 90 degrees and the complement in question would be "x" degrees, with the other angle measuring (2x+42) degrees.
For the second question, note that (diameter)(pi) = (circumference). This formula may be used, since you may substitute 13.47 cm for the circumference and the actual value of pi for pi. Divide both sides of the equation by pi, and you will get the diameter of the circle. Finally, round it to the nearest tenth.
For the last question, realize how QX is the angle bisector of angle PQR, so PQR is split into two angles. This means that Q is the vertex of angle PQR, whereas the angles is split into two congruent angles: angle PQX and angle RQX. You should take the measure of angle PQR and divide that by two to get the measure of angle PQX. I'm sorry to say that I don't really know how to answer this question as well, since technically choice D would work because 180 degrees is the measure of half of a full circle, which measures 360 degrees? Question 3 seems kind of vague. I'd go with the greatest value in the answer choice that is less than 180 degrees.
