Question

area - changing dimensions
what is the formula for the area of a rectangle?
a = lw
a = 2l + 2w
the area of the first rectangle was ____.
a 5
b 10
c 15
the largest area shown in the video is ____.

Explanation:

Step1: Recall the area formula for a rectangle

The formula for the area of a rectangle is \(A = lw\) (where \(l\) is the length and \(w\) is the width).

Step2: Calculate the area of the first rectangle

From the video, for the first rectangle, if \(l = 10\) and \(w = 6\), then \(A=10\times6 = 60\). But wait, looking at the hand - written notes \(A = 10(6)=60\) is wrong. Wait, no, looking at the options for the second question (the area of the first rectangle). Wait, no, re - checking. Wait, in the hand - written notes, there is \(A = 5(3)=15\) (maybe a wrong example) and \(A = 10(6)=60\) (but this is not in the options). Wait, no, looking at the second question (the area of the first rectangle) options: A is 5, B is 10, C is 15. Wait, maybe mis - interpretation. Wait, if we consider the formula \(A=lw\), and if in the first rectangle (from the hand - written notes \(A = 5(3)=15\) is a wrong step, but if we assume that for the first rectangle in the multiple - choice (the second question), if we use \(A=lw\). Wait, no, looking at the second question: the area of the first rectangle. If we assume that the first rectangle in the multiple - choice (the second question) has \(l = 5\) and \(w = 3\) (from the wrong step \(A = 5(3)=15\) in the hand - written notes, but no, wait the options for the second question are A:5, B:10, C:15. Using \(A=lw\), if \(l = 5\) and \(w = 3\), \(A=15\).

Answer:

For the formula of the area of a rectangle: A. \(A = lw\)
For the area of the first rectangle: C. 15