How many different triangles of the same area can be drawn without changing the lengths of two sides?

How many parallels can be drawn through a point not on a line?

In the picture below, two lines are drawn from the top vertex of a triangle to the bottom side: Prove that the ratio in which these lines divide the length of the bottom side is equal to the ratio of the area of the three smaller triangles in the picture.

We have seen how we can draw a series of right triangles as in the picture. What are the lengths of the sides of the tenth triangle? .

How many chords can be drawn through 15 points on a circle?

How many chords can be drawn through 20 points on a circle?

How many chords can be drawn through 21 points on a circle?

In the figure small triangles are drawn joining the mid points of large triangle. Find the length of sides of large triangle.

How many chords can be drawn through 21 points?