Question

Need help finding the missing side of each triangle?

Answer 1

x = 14.5 in

Explanation:

There is something called pythagoras' theorem. It states that

a^2 + b^2 = c^2,

a, b and c being sides of a right-angled triangle.

C is always the hypotenuse and a and b are any of the other two.

(The hypotenuse is always the longest side, and always opposite to the right angle, which is always the biggest angle of a right-angled triangle.)

So here we know two sides, the hypotenuse and another side. Let's substitute them into the formula:

5.8^2 + x^2 = 15.6^2

x^2 = 15.6^2 - 5.8^2

x^2 = 243.36 - 33.64

x^2 = 209.72

x = sqr209.72

x = 7sqr107/5 = 14.48171261 in

= 14.5 in (if rounded to 3 significant figures)

You could use a shortcut to do all this and find the answer more quickly:

a^2 = c^2 - b^2 or b^2 = c^2 - a^2

also:

a = sqr(c^2 - b^2)

x = Sqr(15.6^2 - 5.8^2)

= 14.5 in

Answer 2

This is a right triangle. Use the Pythagorean theorem to solve:

x^2 + 5.8^2 = 15.6^2

x^2 + 33.64 = 243.36

Subtract 33.64 from both sides:

x^2 = 209.72

Take the square root of both sides:

x = 14.48171

Round to 1 decimal place:

x = 14.5 in.