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Understanding the Problem

You have a right triangle where two sides are given: 7 cm and 2 cm. You want to find the length of side B.

Step 1: Identify the sides

The Pythagorean theorem states:

a² + b² = c²

where c is the hypotenuse (the longest side opposite the right angle), and a and b are the other two sides.

First, determine which side is the hypotenuse. Between 7 cm and 2 cm, 7 cm is larger, so likely 7 cm is the hypotenuse or one of the legs. However, the problem doesn't specify which sides these lengths correspond to or which side B is.

Step 2: Clarify what is side B

There are two possible cases:

  1. Case 1: Side B is one of the legs, and the hypotenuse is 7 cm. Then one leg is 2 cm, side B is unknown.
  2. Case 2: Side B is the hypotenuse, and the legs are 7 cm and 2 cm.

Step 3: Solve for side B in each case

Case 1: Hypotenuse = 7 cm, one leg = 2 cm, find B (other leg)

Using the Pythagorean theorem:

b² + 2² = 7²

b² + 4 = 49

Subtract 4 from both sides:

b² = 49 - 4 = 45

Take the square root:

b = √45 = √(9 × 5) = 3√5 ≈ 6.71 cm

Case 2: Legs = 7 cm and 2 cm, find B (hypotenuse)

b² = 7² + 2²

b² = 49 + 4 = 53

Take the square root:

b = √53 ≈ 7.28 cm

Conclusion

So depending on what side B is (a leg or the hypotenuse), the answer is:

  • If B is a leg and hypotenuse is 7 cm: B ≈ 6.71 cm
  • If B is the hypotenuse and legs are 7 cm and 2 cm: B ≈ 7.28 cm

Please confirm which side B represents to use the appropriate solution.


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