Mathematics

Grade6

Easy

Question

# Area of a triangle is given by A = l × b. If l = 10cm and b = 12 cm, then find its area?

- 12 cm
^{2} - 120 cm
^{2}
- 1 cm
^{2}
- 10 cm
^{1}

^{2}^{2}^{2}^{1}Hint:

### The expression for area is an algebraic expression. An algebraic expression consists of two components: a variable and a constant. A variable is a quantity that doesn’t have any fixed value. It takes value according to the conditions. A constant is a quantity with a fixed value. In this question, we are giving the equation for the area of a triangle. The equation consists of two variables, ‘l’ and ‘b’. The variables are assigned some value. We have to substitute the values and perform the operation.

## The correct answer is: 120 cm^{2}

### In this question, we are giving the equation for the area of a triangle. The equation consists of two variables, ‘l’ and ‘b’. The variables are assigned some value. We have to substitute the values and perform the operation.

The given expression is A=l×b.

There are two variables in the above expression: ‘l’ and ‘b’. The variables are assigned some value. The value of l=10 cm and the value of b=12cm.

The variables “l” and “b” have a multiplication sign in between them. So the operation we have to perform is multiplication of the variables.

After substituting the values, we have to perform the multiplication. To substitute the values, we have to replace “l” by 10 and we have to replace “b” by 12.

We get the equation as follows:

A = l × b

A=(10) × (12)

A = 120cm^{2}

Therefore the value of area is 120 cm^{2}

So option (b), which is '120 cm^{2 }', is the right option.

We have to be careful about the operations because the variables. We have to follow proper order for performing the operations. The variables take different values under different conditions. So we have to careful while substituting the values. The main part of such type of questions is just replacing the variables by their value and performing the operation.