In a triangle from one vertex, 20 rays are drawn. How many triangles are there in such a triangle?

To solve this problem, we will find how many triangles will turn out if 20 rays are drawn from one vertex of the triangle. For further consideration of this problem, we will assume that all rays are drawn between two legs of the triangle. Now let’s imagine a triangle in which one ray is drawn, it divides our triangle by two. Now let’s imagine that two rays are drawn in a triangle and there are three triangles. We write the pattern mathematically;

X = a + 1, where X is the number of triangles, and is the number of rays;

Let’s substitute the data;

X = 20 + 1;

X = 21 triangle will turn out.