Question

Difficulty: MediumPythagorean Theorem and Special Right Triangles

In right triangle ABCABC, the right angle is at vertex BB, AB=6AB = 6, and the measure of ACB\angle ACB is 3030^\circ. Point PP lies on segment BCBC such that the measure of APB\angle APB is 6060^\circ. Which of the following statements must be true? Select all that apply.

  1. The length of segment APAP is 434\sqrt{3}.Answer
  2. The length of segment PCPC is 434\sqrt{3}.Answer
  3. C
    The area of triangle APCAPC is 18318\sqrt{3}.
  4. The perimeter of triangle ABCABC is 18+6318 + 6\sqrt{3}.Answer
  5. E
    The length of segment BPBP is 333\sqrt{3}.

Answer

The correct statements are that the length of segment APAP is 434\sqrt{3}, the length of segment PCPC is 434\sqrt{3}, and the perimeter of triangle ABCABC is 18+6318 + 6\sqrt{3}.
The 30-60-90 triangle ratio (1:3:21 : \sqrt{3} : 2) establishes AC=12AC = 12, BC=63BC = 6\sqrt{3}, AP=43AP = 4\sqrt{3}, and BP=23BP = 2\sqrt{3}. Consequently, PC=43PC = 4\sqrt{3} and the perimeter of triangle ABCABC equals 18+6318 + 6\sqrt{3}. Thus, the statements asserting that AP=43AP = 4\sqrt{3}, PC=43PC = 4\sqrt{3}, and the perimeter of triangle ABCABC is 18+6318 + 6\sqrt{3} are all correct.

Step-by-Step Solution

1
Analyze main triangle ABCABC
Hypotenuse AC=12AC = 12 and base BC=63BC = 6\sqrt{3}
Triangle ABCABC is a 30-60-90 triangle with side opposite 3030^\circ equal to AB=6AB = 6. Therefore, hypotenuse AC=2(6)=12AC = 2(6) = 12 and leg BC=63BC = 6\sqrt{3}.
2
Analyze sub-triangle ABPABP
Leg BP=23BP = 2\sqrt{3} and hypotenuse AP=43AP = 4\sqrt{3}
Triangle ABPABP is a 30-60-90 triangle with side opposite 6060^\circ equal to AB=6AB = 6. The shorter leg is BP=63=23BP = \frac{6}{\sqrt{3}} = 2\sqrt{3} and the hypotenuse is AP=2(23)=43AP = 2(2\sqrt{3}) = 4\sqrt{3}.
3
Calculate segment PCPC and area of triangle APCAPC
PC=43PC = 4\sqrt{3} and Area(APC)=123\text{Area}(\triangle APC) = 12\sqrt{3}
PC=BCBP=6323=43PC = BC - BP = 6\sqrt{3} - 2\sqrt{3} = 4\sqrt{3}. The area of APC\triangle APC is 12×PC×AB=12(43)(6)=123\frac{1}{2} \times PC \times AB = \frac{1}{2}(4\sqrt{3})(6) = 12\sqrt{3}.
4
Calculate perimeter of triangle ABCABC
Perimeter =18+63= 18 + 6\sqrt{3}
Sum of sides AB+BC+AC=6+63+12=18+63AB + BC + AC = 6 + 6\sqrt{3} + 12 = 18 + 6\sqrt{3}.

Key Concept

Properties of 30-60-90 Special Right Triangles and Side Length Ratios (1:3:21 : \sqrt{3} : 2)
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