`A (1, -2) and B (2, 5)` are two points. The line OA, OB are produced to C and D respectively such that `OC=2OA and OD=20B`. Find CD

On the xy plane where O is the origin, given points, A(1, 0), B(0, 1) and C(1, 1) . Let P, Q, and R be moving points on the line OA, OB, OC respectively such that overline(OP)=45t overline((OA)),overline(OQ)=60t overline((OB)),overline(OR)=(1-t) overline((OC)) with t>0. If the three points P,Q and R are collinear then the value of t is equal to

Let O(0.0),A(6,0) and B(3,sqrt3) be the vertices of triangle OAB. Let R those points P inside triangle OAB which satisfy d(P, OA) minimum (d(P,OB),d(P,AB) where d(P, OA), d(P, OB) and d(P, AB) represent the distance of P from the sides OA, OB and AFB respectively. If the area of region R is 9 (a -sqrtb) where a and b are coprime, then find the value of (a+ b)

O is any point inside a rectangle ABCD. Prove that OB^(2)+OD^(2)=OA^(2)+OC^(2) . DEDUCTION In the given figure, O is a point inside a rectangle ABCD such that OB=6cm, OD=8 cm and OA=5 cm, find the length of OC.

if D,E and F are the mid-points of the sides BC,CA and AB respectively of the DeltaABC and O be any points, then prove that OA+OB+OC=OD+OE+OF

Points A(a,b,c) and B(b,c,a) are taken such that |OA|=10 ,then the length of the curve describedby A such that the vector vec OA and vec OB are perpendicular is