The two circles below are concentric (have same center). The radius of the large circle is 10 and that of the small circle is 6. What is the length of the chord AB?
Point A is inside the square BCDE whose side length is 20. The length of AB is 9 and the length of AE is 13. Find x the length of AC.
Find all points of intersections of the circle x2 + 2x + y2 + 4y = -1 and the line x - y = 1
Find the area of the triangle enclosed by the x - axis and the lines y = x and y = -2x + 3.
Find the length of the third side of a triangle if the area of the triangle is 18 and two of its sides have lengths of 5 and 10.
In the figure below points A, B, C and D are on a circle. Point O is the intersection of chords AC and BD. The area of triangle BOC is 15; the length of AO is 10 and the length of OB is 5. What is the area of triangle AOD?