Answer:
a) 625; 625; right triangle
b) 205; 256; obtuse triangle
Explanation:
The squares are values found in your memory or using a calculator. It is straightforward addition to find their sum.
left side
7² +24² = 49 +576 = 625
25² = 625
The sum of the squares of the short sides is the square of the long side, so this is a right triangle.
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right side
6² +13² = 36 +169 = 205
16² = 256
The long side is longer than is needed to form a right triangle, so the largest angle is more than 90°. This is an obtuse triangle (as shown).