Lines, Angles, and Triangles 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 Lines, Angles, and Triangles flashcards as text
In triangle ABC, side AB = 7, BC = 24, and angle B = 90°. What is the length of AC?
Answer: 25
AC = √(AB² + BC²) = √(49 + 576) = √625 = 25.
Two angles of a triangle are 54° and 78°. A line is drawn from the third vertex perpendicular to the opposite side. What is the measure of the third angle of the triangle?
Answer: 48°
Third angle = 180° − 54° − 78° = 48°.
Parallel lines r and s are cut by a transversal. A co-interior angle on line r measures (6x + 5)° and the co-interior angle on line s measures (4x + 15)°. What is x?
Answer: 16
Co-interior angles are supplementary: (6x+5)+(4x+15) = 180 → 10x+20 = 180 → x = 16.
An angle bisector divides a 136° angle into two equal parts. What is the measure of each part?
Answer: 68°
Each part = 136° / 2 = 68°.
Triangle XYZ is similar to triangle PQR. If XY = 12, YZ = 16, and PQ = 9, what is QR?
Answer: 12
Ratio = PQ/XY = 9/12 = 3/4; QR = YZ × 3/4 = 16 × 3/4 = 12.
Lines m and n are parallel. A transversal creates an angle of 117° on line m. What is the measure of the alternate interior angle on line n?
Answer: 117°
Alternate interior angles are equal when lines are parallel, so the angle is 117°.
In a right triangle, the two acute angles are in the ratio 1:5. What is the measure of the larger acute angle?
Answer: 75°
Two acute angles sum to 90°; ratio 1:5 → 6 parts = 90° → each part = 15°; larger = 5 × 15° = 75°.