Question

Which group of measurements could be the side lengths of a right triangle?

A.
57 in, 86 in, 95 in
B.
47 in, 76 in, 95 in
C.
57 in, 76 in, 95 in
D.
57 in, 76 in, 105 in

Answer 1

In right angled triangles, according to Pythagoras' theorem, squared of the hypotenuse is equal to the sum of the squares of the other 2 sides of the triangle.
if the hypotenuse is H and other 2 sides are A and B, then equation is as follows;
H² = A² + B²

1. A - 57 in. B - 86 in.
H² = A² + B²
H² = 57² + 86²
H² = 3249 + 7396
H = √10645
= 103.17 in.
third side given is not 103 in therefore this is not a right angled triangle

2. A - 47 in. B - 76 in.
H² = A² + B²
H² = 47² + 76²
= 2209 + 5776
H = √7985
H = 89.3 in.
third side given is 95 in. therefore this is not a right angled triangle.

3. A- 57 in. + B - 76 in.
H² = A² + B²
H² = 57² + 76²
= 3249 + 5776
H = √9025
H = 95 in.
third side given is 95 in. therefore this is a right angled triangle.

4. A - 57 in. B - 76 in.
As calculated in the third equation with the same side lengths of A and B, hypotenuse should be 95 in. however the third side length given is 105 in. so this is not a right angle triangle