Two sides of a square are divided into fourths and another side of the square is trisected, as shown. A triangle is formed by connecting three of these points, as shown. What is the ratio of the area of the shaded triangle to the area of the square? Express your answer as a fraction.

Explanation:

Let's say this is a 1 by 1 square. The area is 1*1 = 1 square unit. Whatever the area of the triangle is, we divide it over 1 and it will yield the same value as the area of the triangle. In other words, the area of the triangle will be the answer.

Along the top we have 3 ticks to indicate the top segment has been cut into 3+1 = 4 equal parts. The horizontal distance from the the vertical side of the triangle to the peak of the triangle is 3/4 units. This is because we travel 3 ticks out of 4 total. So this is the height when we consider the vertical segment of the triangle to be the base.

The base is 1 unit as it spans the original square's side length

base = 1

height = 3/4

area of triangle = (1/2)*(base*height)

area of triangle = (1/2)*(1*3/4)

area of triangle = 3/8

ratio of triangle area to square area = (triangle area)/(square area)

ratio of triangle area to square area = (3/8)/1

3/8

Step-by-step explanation:

let side of square=x

Area of a square =x^2

height of a triangle= 3x/4  ( 4/4=1/4) since height is only 3x/4 from the square)

( base =x same side as a square)

Area of a triangle=1/2 bh=1/2(x*3x/4)= 3x^2/8

the ratio of shaded triangle to the area= (3x^2/8)/x^2=3x^2/8x^2=3/8