l and m are two parallel lines intersected by another pair of parallel lines p and q. Show that `triangleABC ~= triangleCDA`

l and m are two parallel lines intersected by another pair of parallel lines p and q . Show that DeltaABC~= DeltaCDA .

The number of parallelograms that can be formed from a set of four parallel lines intersecting another set of three parallel line intersecting another set of three parallel lines is:

l, m and n are three parallel lines intersected by the transversals p and q at A, B, C and D,E, F such that they make equal intercepts AB and BC on the transversal p. Show that the intercepts DE and EF on q are also equal.

m parallel lines in a plane are intersected by a family of n parallel lines. The total number of parallelograms so formed is :

Does Euclid's fifth postulate imply the existence of parallel lines? Explain .

ABC is an equilateral triangle such that the vertices B and C lie on two parallel lines at a distance 6. If A lies between the parallel lines at a distance 4 from one of them, then the length of a side of the equilateral triangle is :

A line intersecting a circle in two points is called a secant .

The side AB of a parallelogram ABCD is produced to any point P. A line through A and parallel to CP meets CB produced at Q and then parallelogram PBQR is completed . Show that ar (ABCD) = ar (PBQR)

Fill in the blanks: If two lines intersect at a point, and if one pair of vertically opposite angels are acute angles, then the other pair of vertically opposite angles are ______.