每日一题

Mathematics>Standard Multiple Choice

Read the following SAT test question and then click on a button to select your answer.

In triangle A B C, the sum of the measures of angle A and angle B is 70 degrees. The measure of angle A is one-half the measure of angle B. If the measure of angle B is equal to x degrees, which of the following expressions represents the sum of angles A, B and C?

A.x+2x+110
B.x/2+x+110
C.1/2(x+2x+110)
D.x/2+x+70

答案和解析

答案：B

解析：

Choice B is correct. The sum of the three interior angles in a triangle is 180 degrees. If the measures of two interior angles in the triangle sum to 70 degrees, then the third angle must measure 110 degrees. If the measure of angle B is x and the measure of angle A is one-half of the measure of angle B comma then the measure of angle A is x/2. Therefore, x/2+x+110 is the sum of the measures of the angles in triangle ABC.