Right Triangles and Trigonometry Flashcards
7 cards from real Bluebook SAT Test practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Right Triangles and Trigonometry flashcards as text
In right triangle ABC with the right angle at C, if sin(A) = 2/3, what is the value of sin²(A) + cos²(A)?
Answer: 1
The Pythagorean identity states sin²(θ) + cos²(θ) = 1 for any angle θ.
A right triangle has legs of length 7 and 24. What is the value of sin of the angle opposite the leg of length 7?
Answer: 7/25
The hypotenuse is √(7² + 24²) = √(49 + 576) = √625 = 25, so sin = opposite/hypotenuse = 7/25.
In a 30-60-90 right triangle, if the hypotenuse has length 8, what is the length of the side opposite the 60° angle?
Answer: 4√3
In a 30-60-90 triangle, the sides are in ratio 1 : √3 : 2, so the side opposite 60° = (8/2)·√3 = 4√3.
Right triangle PQR has the right angle at R. If cos(P) = 5/13, what is tan(P)?
Answer: 12/5
If cos(P) = 5/13, then the adjacent leg is 5 and hypotenuse is 13, so the opposite leg is √(169 − 25) = 12, giving tan(P) = 12/5.
A 10-foot ladder leans against a vertical wall. The base of the ladder is 6 feet from the wall. At what angle, to the nearest degree, does the ladder make with the ground?
Answer: 53°
cos(θ) = 6/10 = 0.6, so θ = cos⁻¹(0.6) ≈ 53°.
In right triangle ABC with right angle at C, AB = 10 and AC = 6. What is sin(B)?
Answer: 3/5
AC = 6 is adjacent to B, AB = 10 is the hypotenuse, so BC = √(100 − 36) = 8. sin(B) = opposite/hypotenuse = AC/AB = 6/10 = 3/5.
Two right triangles are similar. The first has legs 6 and 8. The hypotenuse of the second triangle is 25. What is the perimeter of the second triangle?
Answer: 60
The first triangle has hypotenuse √(36+64) = 10. Scale factor = 25/10 = 2.5. Legs of the second = 6×2.5 = 15 and 8×2.5 = 20. Perimeter = 15 + 20 + 25 = 60.