Hey! Even I'm in Grade 10. Here are some questions I found as important or interesting. Hope it helps...
1. A cone, a hemisphere and a cylinder stand on equal bases and have same height. Then find ratio of their volumes.
2. Prove that the intercept of a tangent between two parallel tangents to a circle subtends a right angle at the centre of the circle.
3. If a, b, c are the sides of a right triangle where c is the hypotenuse, and it contains a circle that touches all sides of the triangle, then prove that r = (a+b-c)/2.
4. A birthday conical cap is cut by a plane parallel to its base and upper part is used for a new cap for a toy, The CSA of the new cap is 1/9 the CSA of the whole cone. Find the ratio of the line segments into which the cones altitude is divided by the plane.
5. If PAB is a secant to a circle intersecting the circle to A and B and PT is a tangent. Prove that PA×PB = PT².