Rectangle Perimeter: Calculate ABCD with Equal Segments CE and AB

Question

Look at the following rectangle:

AAABBBCCCDDDFFFEEE31117

CE = AB

Calculate the perimeter of rectangle ABCD.

Video Solution

Solution Steps

00:00 Calculate the perimeter of rectangle ABCD
00:03 Opposite sides are equal in a rectangle
00:11 Segment FC equals the entire side (BC) minus segment (BF)
00:16 Let's substitute appropriate values according to the given data and solve for FC
00:31 This is the height FC
00:35 We'll use the Pythagorean theorem in triangle FCE to find CE
00:45 Let's substitute appropriate values and solve for CE
01:02 Let's isolate CE
01:21 This is the length of side CE
01:26 Sides are equal according to the given data
01:35 Opposite sides are equal in a rectangle
01:48 The perimeter of the rectangle equals the sum of its sides
01:52 Let's substitute appropriate values and solve for the perimeter
02:15 And this is the solution to the problem

Step-by-Step Solution

Since in a rectangle every pair of opposite sides are equal to each other, we can claim that:

AD=BC=11 AD=BC=11

We can calculate side FC:

113=FC 11-3=FC

8=FC 8=FC

Let's focus on triangle FCE and calculate side CE using the Pythagorean theorem:

CF2+CE2=FE2 CF^2+CE^2=FE^2

Let's substitute the known values into the formula:

82+CE2=172 8^2+CE^2=17^2

64+CE2=289 64+CE^2=289

CE2=28964 CE^2=289-64

CE2=225 CE^2=225

Let's take the square root:

CE=15 CE=15

Since CE equals AB and in a rectangle every pair of opposite sides are equal to each other, we can claim that:

CE=AB=CD=15 CE=AB=CD=15

Now we can calculate the perimeter of the rectangle:

11+15+11+15=22+30=52 11+15+11+15=22+30=52

Answer

52