Right Triangle Area Problem: Find BC When Area = 38 cm² and AC = 8 cm

Question

The triangle ABC is a right triangle.

The area of the triangle is 38 cm².

AC = 8

Calculate side BC.

S=38S=38S=38888AAABBBCCC

Video Solution

Solution Steps

00:00 Determine the height BC
00:03 Examine the size of the sides and lines according to the given data
00:08 Apply the formula for calculating the area of a triangle
00:16 (height x base) divided by 2
00:20 Substitute in the relevant values and proceed to solve for BC
00:36 Multiply by denominators in order to eliminate fractions
00:52 Isolate BC
01:05 This is the solution

Step-by-Step Solution

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

  • Step 1: Identify the area formula related to a right triangle.
  • Step 2: Set up an equation with the given area and known side.
  • Step 3: Solve for the unknown side BC BC .

Step 1: We know the area A A of a right triangle is given by the formula:
A=12×base×height A = \frac{1}{2} \times \text{base} \times \text{height} .

Step 2: Using the known values, A=38cm2 A = 38 \, \text{cm}^2 , the side AC=8cm \text{AC} = 8 \, \text{cm} and assuming it acts as the base, we set up the equation:
38=12×8×BC 38 = \frac{1}{2} \times 8 \times \text{BC} .

Step 3: Simplify to solve for BC \text{BC} :
Multiply both sides by 2 to eliminate the fraction:
76=8×BC 76 = 8 \times \text{BC} .
Now, divide both sides by 8 to find BC \text{BC} :
BC=768 \text{BC} = \frac{76}{8} .
BC=9.5cm \text{BC} = 9.5 \, \text{cm} .

Therefore, the length of side BC BC is 9.5 cm.

Answer

9.5 cm