Calculate Rectangle Perimeter with Congruent Triangles: 6x8 Geometric Figure

Question

ΔAED≅ΔBCD

Calculate the perimeter of the rectangle AFDE.

AAABBBCCCEEEDDDFFF68

Video Solution

Solution Steps

00:00 Determine the perimeter of the rectangle AFDE
00:03 The triangles are congruent according to the given data
00:15 The sides are equal according to the theory of congruence
00:22 Substitute in the relevant values according to the given data
00:41 The opposite sides in a rectangle are equal
00:54 The perimeter of the rectangle equals the sum of its sides
01:05 Substitute in the relevant values and solve to determine the perimeter
01:26 This is the solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Analyze the congruent triangles.

  • Step 2: Use congruence to identify side lengths.

  • Step 3: Calculate the perimeter of the rectangle.

Now, let's work through each step:
Step 1: The problem states that AEDBCD\triangle AED \cong \triangle BCD, which means corresponding sides and angles are equal.
Step 2: Identify corresponding sides from congruence:
- AE=CD=6AE = CD = 6 because corresponding sides of congruent triangles are equal.
- AD=BCAD = BC. Since AB=8AB = 8 and using the fact AED\triangle AED and BCD\triangle BCD are congruent, BDBD (the same as ADAD) must also equal 6 (from the congruence starting from point DD).
- Thus, AD=6AD = 6.

Step 3: Calculate the perimeter: AF=DE=6AF = DE = 6 from congruency and AD=FE=6AD = FE = 6. Since both pairs of opposite sides of the rectangle are equal, the rectangle perimeter is:
P=2(AF+AD)=2(6+8)=2×14=28 P = 2(AF + AD) = 2(6 + 8) = 2 \times 14 = 28

Therefore, the perimeter of the rectangle AFDEAFDE is 2828.

Answer

28