How many triangles are there in a regular pentagon with all its diagonals drawn?
Note: a regular pentagon has five straight sides all of the same length and five equal angles. A diagonal is a line joining points.
A regular Pentagon with all its diagonals drawn will have 10 vertices { 5 inner and 5 outer vertices }. Now to draw a triangle we need exactly 3 vertices. So the answer to the question becomes 5 Choose 3 or 5C3 = 10 + (the triangles made by using 1 or more inner vertices) 15 = 35 which is also the number of triangles obtainable from the above figure.
A right trapezoid is partitioned into 4 triangles by its diagonals, as shown:
Which colored region has a largest area?
There are 20 points arranged in a cross pattern shown below. How many squares can be drawn, using any 4 points as corners?
Every other side of a regular decagon is extended to form a regular pentagon, find the ratio of two shaded regions?
The area of the small regular pentagon is A. The area of the big regular pentagon is B. What is A/B?
A five pointed star is made by extending sides of a regular pentagon. What fraction of star on right is shaded yellow?
