Hint: In this question , use $2(l + b)$ i.e. the perimeter of a rectangle to find the perimeter of the given figure. Complete step-by-step solution - According to the question we have to find the perimeter of the given figure i.e. rectangle. Hence, it is given Length of the rectangle $(l) = 40cm$ Breadth of the rectangle $(b) = 20cm$ We know that perimeter of rectangle $ = 2(l + b)$ Hence , substituting the value of $l$ and $b$ in the formula we get, $ = 2(40 + 20) \\ = 2(60) \\ = 120cm \\ $ $\therefore $ The perimeter of the figure is $120cm$.
Note: It is always advisable to remember such basic formulas while involving in such types of questions as it helps save a lot of time . Eventually it’s difficult to mug up every formula but with practice things get easier.