Answer:
Number 1 can form a right triangle. Numbers 2 & 3 cannot.
Step-by-step explanation:
To check if the sides are a right triangle, check if the sum of the squares of the two smaller sides equals the length of the square of the longest side. In other words, do the Pythagorean Theorem.
5² + 12² = 13²
25 + 144 = 169
169 = 169
They are equal therefore Number 1 can form a right triangle.
5² + 7² = 9²
25 + 49 = 81
74 = 81
They are not equal, therefore Number 2 can't form a right triangle.
10² + 12² = 30²
100 + 144 = 900
244 = 900
They are not equal, therefore Number 3 can't form a right triangle.
