Đề thi Olympic Tiếng Anh lớp 9 vòng 24 năm 2013 - 2014

AD // CB and cut by transversal AB. AC ⊥ CB. AB = 10, ∠DAB = 35°. Which of the following expressions could be used to determine the length of AC?

What is the area, in square inches, of the circle that is circumscribed about an equilateral triangle that has a perimeter of 36 inches?

The apothem (drawn from the center, perpendicular to a side) of a regular hexagon has a length of 6. What is the perimeter of the hexagon?

Trapezoid ABCD is inscribed in circle P. If AB ≌ BC ≌ CD and AP = 12, what is the measure of the median of the trapezoid?

First rotate the triangle bounded by the vertices (0, 0), (0, 5), (4, 0) about the origin 180°. Then, reflect the resulting image across the x-axis. What quadrant contains the final image of the triangle after both transformations?

Theorem: A triangle has at most one obtuse angle. Eduardo is proving the theorem above by contradiction. He began by assuming that in ΔABC, ∠A and ∠B are both obtuse. Which theorem will Eduardo use to reach a contradiction?

Two lines in a plane always intersect in exactly one point.

Which of the following best describes a counterexample to the assertion above?

Which triangles must be similar?

Water flows into a container at a constant rate. The equation w = 4t + 10 shows how the amount of water, w, in gallons, in the container relates to the amount of time, t, in minutes, since the water began to flow. What does the 10 in the equation represent?

The diagram above shows a construction of cube blocks. What is the view of the right side?