SAT Math Multiple Choice Question 957: Answer and Explanation
Note: Figure not drawn to scale.
Ifand, what is the length of side AB?
- B. 12
- D. 18
Correct Answer: D
Category: Additional Topics in Math / Geometry
Strategic Advice: Whenever you're given a figure, transfer as much information as possible from the question to the figure, and then label the figure with any additional calculations you make.
Getting to the Answer: Because, ΔBDC is an isosceles right triangle (and therefore a 45-45-90 triangle). You're told that the two legs both measure 6, which means that hypotenuse measures. You also know that AD = 2CD, so. Next, use the Pythagorean theorem to find AB:
So, making (D) the correct answer.