Answer:
d. 21.5
Step-by-step explanation:
To find the missing side length of each triangle, use the pythagorean theorem. The theorem is [tex]a^2 + b^2 = c^2[/tex] where a, b, and c are all side lengths of the triangle. a is the smallest lef and b is the other leg while c is always the hypotenuse or longest side.
In d, you'll use it twice to find the missing measure. First use it when a = 12 and b = 20. So you'll have:
[tex]12^2 + 20^2 = c^2\\144 + 400 = c^2\\544 = c^2\\\sqrt{544} = c\\ 23.32 = c[/tex]
Repeat the same process using a = 9 and c = 23.32. Then solve for the b value.
[tex]9^2 + b^2 = 23.32^2\\81 + b^2 = 544\\b^2 = 544 - 81\\b^2 = 463\\b = \sqrt{463} \\b = 21.5[/tex]
