Question in-rig
In right triangle , angle is the right angle and . Point on side is connected by a line segment with point on side such that line segment is parallel to side and . What is the length of line segment ?
In right triangle A B C , angle C is the right angle and B C
Hard-difficulty · SAT Math · Lines, Angles, and Triangles — Angle relationships (parallel lines). Read the question above, select your answer, and check the full explanation below to understand exactly why the correct choice works.
Answer explanation
The correct answer is . It’s given that in triangle , point on side is connected by a line segment with point on side such that line segment is parallel to side . It follows that parallel segments and are intersected by sides and . If two parallel segments are intersected by a third segment, corresponding angles are congruent. Thus, corresponding angles and are congruent and corresponding angles and are congruent. Since triangle has two angles that are each congruent to an angle in triangle , triangle is similar to triangle by the angle-angle similarity postulate, where side corresponds to side , and side corresponds to side . Since the lengths of corresponding sides in similar triangles are proportional, it follows that . Since point lies on side , . It's given that . Substituting for in the equation yields , or . It’s given that . Substituting for and for in the equation yields , or . Multiplying both sides of this equation by yields . Thus, the length of line segment is .
More Lines, Angles, and Triangles practice questions
- Counterclockwise from top right, the lines are labeled s, r, q, and t. Line
- In △ R S T , the measure of ∠ R is 63 °
- Clockwise from top left, the 3 lines are labeled t, m, and n. Line
- In triangle X Y Z , angle Y is a right angle, point P
- At the intersection of the 2 lines, the angles are labeled clockwise from top
- Triangles A B C and D E F are congruent, where A corresponds to
- Clockwise from top left, the 3 lines are labeled t, p, and q. Line
- A circle has center O , and points R and S lie on the
Browse all Additional Topics in Math practice questions or return to the full SAT question bank.
