Final answer:
The measure of each base angle in the isosceles triangle is 30 degrees, and the third angle is 120 degrees.
Step-by-step explanation:
The problem involves finding the measure of each angle of an isosceles triangle given that the third angle is 30 degrees more than three times as large as each of the two base angles. Since the sum of the angles in any triangle equals 180 degrees, we can set up an equation to solve for the base angles.
Let x represent the measure of the base angle. The third angle will then be expressed as 3x + 30. Since the triangle is isosceles, it has two equal base angles, so we have:
Simplifying the equation gives us 5x + 30 = 180. To find x, subtract 30 from both sides to get 5x = 150, and then divide both sides by 5 to get x = 30. The measure of the base angles is 30 degrees each, and the third angle, being 3 times 30 plus 30, is 120 degrees.
Therefore, the measure of each angle in the isosceles triangle is 30 degrees for both base angles and 120 degrees for the third angle, which corresponds to option B) 30°, 60°, 60°, making it a misprint. The correct answer should be 30°, 30°, 120°.