Triangle Median Problem: Finding AC Length When BC = AC

Question

If AD is the median.

and BC is equal to AC

Determine the length of the side AC.

AAABBBCCCDDD5

Video Solution

Solution Steps

00:00 Calculate the side AC
00:03 AD is a median according to the given information. The median bisects the side
00:08 Insert the value of BD into the formula, according to the given information
00:14 The entire side equals the sum of its parts
00:20 Substitute in the relevant values and proceed to solve to find BC
00:27 The sides are equal according to the given information
00:33 This is the solution

Step-by-Step Solution

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

  • Step 1: Identify the given information that AD AD is the median making BD=CD=5 BD = CD = 5 .
  • Step 2: Use the triangle property that BC=AC BC = AC as per the problem’s isosceles condition.
  • Step 3: Calculate BC=BD+CD=5+5=10 BC = BD + CD = 5 + 5 = 10 .
  • Step 4: Since BC=AC BC = AC , by isosceles property, conclude AC=10 AC = 10 .

Now, let's work through each step:
Step 1: With AD AD as the median, it divides BC BC into BD=5 BD = 5 and CD=5 CD = 5 .
Step 2: The condition BC=AC BC = AC ensures the triangle is isosceles.
Step 3: Calculate BC BC as BD+CD=5+5=10 BD + CD = 5 + 5 = 10 .
Step 4: Since BC=AC BC = AC , therefore, AC=10 AC = 10 .

Therefore, the length of AC AC is 10 10 .

Answer

10