In a maths class of 26 students, each girl drew a triangle and each boy drew a rectangle. if there were 92 sides drawn by the students, how many girls were in the class?

Let there be x girls, and y boys.

Since a triangle is 3 sides, the girls would draw 3x sides.

Since a rectangle is 4 sides, the boys would draw 4y sides.

Recall a total of 92 sides were drawn.

x + y = 26 ... (a)

3x + 4y = 92 ... (b)

From (a) y = 26 - x, substituting this into (b)

3x + 4 * (26 - x) = 92

3x + 104 - 4x = 92

3x - 4x = 92 - 104

-x = - 12

x = - 12/-1 = 12.

Since x is the number of girls, so there are 12 girls

Let the number of girls be g.

Let the number of boys be b.

Now we can write these equations;

3g + 4b = 92 ... (1)

g + b = 26 ... (2)

b = 26 - g ... (3)

Plugging the expression for b in (3) into (1), we get:

3g + 104 - 4g = 92 ... (4)

Solving (4) we get

g = 12

So the number of girls in the class is 12.