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 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.

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