Question

Two sides of a right triangle have the lengths 4 and 5. What is the product of the possible lengths of the third side? Express the product as a decimal rounded to the nearest tenth.

Answer 1

19.2

Explanation:

1st Case:

4 and 5 are legs of the right triangle.

Using the pythagorean therom: a^2+b^2=c^2

We can say that 4^2+5^2=x^2

16+25=x^2

41=x^2

x=√41

√41 is about 6.4

x=6.4

2nd Case

5 is the hypotenuse of the right triangle and 4 is the legs.

Using the pythagorean therom: a^2+b^2=c^2

We can say that 4^2+x^2=5^2

16+x^2=25

x^2=9

x=3

Final Step

We need to multiply the two possible lengths for x. So for case 1 the length of x was 6.4 and for case two the length was 3. 6.4*3=19.2

Anwser: 19.2