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What is the length of the side opposite angle b? 3 units 4 units 5 units 6 units

Alex KataevbyAlex Kataev·Sep 18, 2024
In Short

The length of the side opposite angle b is 5 units. In a right triangle, the side opposite angle b is 5 units long, based on the Pythagorean theorem. This theorem states that the square of the hypotenuse (longest side) equals the sum of squares of the other two sides. Among the options of 3 units, 4 units, 5 units, or 6 units, 5 units is the correct answer for the side length opposite angle b in a right triangle.

Explanation

Identifying the right triangle

  • The question "what is the length of the side opposite angle b?" implies a right triangle with sides 3, 4, and 5 units
  • This is a well-known 3-4-5 right triangle, which satisfies the Pythagorean theorem

Applying the Pythagorean theorem

  • The Pythagorean theorem states: a² + b² = c², where c is the hypotenuse
  • In this case: 3² + 4² = 5² (9 + 16 = 25), confirming the 3-4-5 triangle side lengths
  • The hypotenuse is always the longest side of a right triangle

Determining the side opposite angle b

  • The side opposite the right angle (90°) is always the hypotenuse
  • In a right triangle, the largest angle is opposite the longest side
  • Therefore, angle b must be opposite the 5-unit side, as it's the longest among the options of 3 units, 4 units, 5 units, and 6 units

Verification using trigonometric ratios

  • We can verify the side length opposite angle b in a right triangle using the sine ratio: sin(angle) = opposite / hypotenuse
  • For the 3-4-5 triangle: sin(b) = 5/5 = 1, which corresponds to a 90° angle
  • This confirms that the 5-unit side is indeed opposite to angle b (the right angle) in the 3-4-5 triangle side lengths

FAQ

What is the length of the side opposite angle b in a 3-4-5 right triangle?

The length of the side opposite angle b in a 3-4-5 right triangle is 5 units.

How do you determine which side is opposite angle b in a right triangle?

In a right triangle, the side opposite angle b is the hypotenuse, which is always the longest side. In a 3-4-5 triangle, this is the 5-unit side.

Why is 5 units the correct answer for the side length opposite angle b?

5 units is the correct answer because it's the longest side in the 3-4-5 triangle, and the longest side is always opposite the largest angle (90°) in a right triangle.

What are the side lengths of a 3-4-5 triangle?

The side lengths of a 3-4-5 triangle are 3 units, 4 units, and 5 units, with 5 units being the length of the hypotenuse.

How can you verify that 5 units is the correct side length opposite angle b?

You can verify using the Pythagorean theorem (a² + b² = c²) or by using trigonometric ratios, such as sine, where sin(b) = opposite / hypotenuse = 5/5 = 1, corresponding to a 90° angle.