Area Calculation: Finding Parallelogram Area Using Rectangle Area of 35 cm²

Question

ABCD is a parallelogram and AEFD is a rectangle.

AE = 7

The area of AEFD is 35 cm².

CF = 2

What is the area of the parallelogram?

S=35S=35S=35777222AAAEEEDDDFFFCCCBBB

Video Solution

Solution Steps

00:00 Find the area of parallelogram ABDC
00:04 We'll use the formula for rectangle area: side(AE) multiplied by side(ED)
00:11 We'll substitute appropriate values and solve for ED
00:14 Let's isolate ED
00:19 This is the length of side ED
00:26 Opposite sides are equal in a rectangle
00:30 The whole side equals the sum of its parts
00:41 Now we'll use the formula for parallelogram area
00:44 height(ED) multiplied by base(CD)
00:47 We'll substitute appropriate values and solve for the area
00:50 And this is the solution to the problem

Step-by-Step Solution

Let's first calculate the sides of the rectangle:

AEDF=AE×ED AEDF=AE\times ED

Let's input the known data:

35=7×ED 35=7\times ED

Let's divide the two legs by 7:

ED=5 ED=5

Since AEDF is a rectangle, we can claim that:

ED=FD=7

Let's calculate side CD:

2+7=9 2+7=9

Let's calculate the area of parallelogram ABCD:

ABCD=CD×ED ABCD=CD\times ED

Let's input the known data:

ABCD=9×5=45 ABCD=9\times5=45

Answer

45 cm².