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The hypotenuse of a right angled triangle is 8 cm more than its shortest side. The third side is 1 cm shorter than the hypotenuse. Find the three sides of ths is triangle.​

User Bentael
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1 Answer

8 votes
8 votes

Answer:

hypotenuse = 13

shortest side = 5

third side = 12

Explanation:

Given sides a, b, and c, with c representing the hypotenuse of a right triangle, we can say that

a²+b² = c² using the Pythagorean Theorem.

We are given that the hypotenuse (c) = 8 cm more than the shortest side. Representing the shortest side as a, we can say that c= 8 + a. Then, the third side, which we can represent as b, is 1cm shorter than the hypotenuse, so c-1 = b

c= 8+a

c-1 = b

a²+b² = c²

One thing we can do is to solve for everything in terms of c and solve the third equation from there

c= 8+a

subtract 8 from both sides

c-8 = a

a²+b² = c²

(c-8)²+b² =c²

b = c-1

(c-8)² + (c-1)² = c²

expand

c²-16c + 64 + c² - 2c + 1 = c²

2c² - 18c + 65 = c²

subtract c² from both sides to make this an equation that we can more easily solve

c² - 18c + 65 = 0

To factor, we can find two numbers that add to (-18) and multiply to 65. Two numbers that work at 13 and 5, so we have

c²-13c-5c + 65 = 0

c(c-13) -5(c-13) = 0

(c-5)(c-13) = 0

Therefore, the hypotenuse, or c, is 5 or 13. Because a=c-8, if c=5, a would be negative 3. This is not possible, so c cannot be 5. Therefore, c=13, a=c-8=5, and b=c-1= 12

User Vold
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