Saved Bookmarks
| 1. |
In a quadrilateral OABC, D is the midpoint of BC and E is the point on AD suchthat AE : ED = 2 : 1. Given that OA = a, OB = b and OC = c, express OD andOE in terms of a, b and c. |
|
Answer» CB=OB-OC; CD=CB/2=(OB-OC)/2=(b-c)/2; OD=OC+CD=c+(b-c)/2=c/2+b/2; AD=OD-OA=c/2+b/2-a; AE=2/3*AD=2/3*(c/2+b/2-a)=c/3+b/3-2*a/3; OE=OA+AE=a+c/3+b/3-2*a/3=a/3+b/3+c/3; OD=c/2+b/2; OE=a/3+b/3+c/3; |
|