Question

The triangle below is isosceles. Find the length of side x in simplest radical form with

a rational denominator.
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4

Answer 1

x = 2√2

Explanation:

Since the triangle is isosceles, it means 2 of the angles are equal and 2 of the sides are also equal.

Now, since we see that it is also a right angled triangle, it means one angle is 90°.

Let the equal angles be a.

Thus;

a + a + 90 = 180 (since sum of angles in a triangle is 180)

2a + 90 = 180

2a = 180 - 90

2a = 90

a = 90/2

a = 45°

Now, using sine rule, we can find x. Thus;

x/sin 45 = 4/sin 90

sin 90 = 1

sin 45 = 1/√2

Thus;

x = (4 × 1/√2)/1

x = 4/√2

Let's rationalize the denominator to get;

x = (4/√2) × √2/√2

x = (4√2)/2

x = 2√2