Question

Im very confused on finding y
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Answer 1

7√2

Explanation:

By observation, we can determine that because this is a right angle triangle with one of the internal angles = 45°, that the remaining unknown angle is also 45°, which makes this an isosceles triangle.

This means that x = 7

we can find y by using the Pythagorean equation:

y² = x² + 7²

y² = 7² + 7²

y² = 98

y = √98 = 7√2

Answer 2

In this case, you can use the concept of cosine to calculate y, and things are even easier when you have one of the special angles which is a 45° angle.

So we know that: cos45° = √2/2

This fact will always be true. In our case, we have:

cos45° = 7/y

Therefore, we have the equation:

7/y = √2/2

⇔ 14 = y√2

⇔ y = 14/√2

⇔ y = √196/√2 = √(196/2) = √98 = 7√2

So y is equal to 7√2