Triangle Area 21: Calculate the Height X with Base 7

Question

The area of the triangle below is equal to 21.

Calculate X.

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Video Solution

Solution Steps

00:05 Let's find the height, X.
00:08 We'll use the triangle area formula.
00:11 It's Base B C times height A E, divided by 2.
00:16 Now, plug in the numbers and solve for height, X.
00:26 Double it to get rid of the fraction.
00:32 Keep solving until you isolate X.
00:42 And that's how we find the solution!

Step-by-Step Solution

To solve this problem, let's apply the following steps:

  • Step 1: Identify the formula for the area of a triangle, which is A=12×base×height A = \frac{1}{2} \times \text{base} \times \text{height} .
  • Step 2: Substitute the known values into the formula: 21=12×7×x 21 = \frac{1}{2} \times 7 \times x .
  • Step 3: Simplify and solve the equation for x x .

Now, let's work through each step more precisely:
Step 1: We're given the area formula as A=12×b×h A = \frac{1}{2} \times b \times h .
Step 2: Substitute in the known values: the area A=21 A = 21 , the base b=7 b = 7 , and the height h=x h = x , leading to the equation 21=12×7×x 21 = \frac{1}{2} \times 7 \times x .
Step 3: Solve for x x – first simplify the multiplication on the right: 21=72×x 21 = \frac{7}{2} \times x .
Step 4: To isolate x x , multiply both sides by 2 to get 42=7x 42 = 7x .
Step 5: Finally, divide both sides by 7 to solve for x x : x=427=6 x = \frac{42}{7} = 6 .

Therefore, the value of x x is 6 6 .

Answer

6