If secA + tanA = a, then the value of cosA is
PQ and RS are common tangents to two circles intersecting at A and B. AB, when produced both sides, meet the tangents PQ and RS at X and Y, respectively. If AB = 3 cm, XY = 5 cm, then PQ (in cm) will be
If O is the orthocentre of a triangle ABC and ∠BOC = 100°, the measure of ∠BAC is
Diagonals of a Trapezium ABCD with AB CD intersect each other at the point O. If AB = 2CD, then the ratio of the areas of ΔAOB and ΔCOD is
D and E are points on the sides AB and AC respectively of ΔABC such that DE is parallel to BC and AD:DB = 4:5, CD and BE intersect each other at F. Then the ratio of the areas of ΔDEF and ΔCBF
ΔABC is an isosceles right angled triangle having ∠C = 90°. If D is any point on AB, then AD2+ BD2 is equal to