Answer:
[tex]\boxed {\boxed {\sf 8.7}}[/tex]
Step-by-step explanation:
We are asked to find the length of the third side in a triangle, given the other 2 sides.
Since this is a right triangle (note the small square in the corner of the triangle representing a 90 degree /right angle), we can use the Pythagorean Theorem.
[tex]a^2 + b^2 =c^2[/tex]
In this theorem, a and b are the legs of the triangle and c is the hypotenuse.
We know that the unknown side (we can say it is a) and the side measuring 5 are the legs because they form the right angle. The side measuring 10 is the hypotenuse because it is opposite the right angle.
Substitute the values into the formula.
[tex]a^2 + (5)^2 = (10)^2[/tex]
Solve the exponents.
[tex]a^2 + 25=100[/tex]
We are solving for a, so we must isolate the variable. 25 is being added to a. The inverse operation of addition is subtraction, so we subtract 25 from both sides.
[tex]a^2 +25-25=100-25[/tex]
[tex]a^2=100-25[/tex]
[tex]a^2 = 75[/tex]
a is being squared. The inverse of a square is the square root, so we take the square root of both sides.
[tex]\sqrt {a^2}= \sqrt{75}[/tex]
[tex]a= \sqrt{75}[/tex]
[tex]a= 8.660254038[/tex]
Round to the nearest tenth. The 6 in the hundredth place tells us to round the 6 up to a 7 in the tenth place.
[tex]a \approx 8.7[/tex]
The length of the third side is approximately 8.7
Using Pythagorean theorem
[tex]\boxed{\sf B^2=H^2-P^2}[/tex]
[tex]\\ \sf \longmapsto B^2=10^2-5^2[/tex]
[tex]\\ \sf \longmapsto B^2=100-25[/tex]
[tex]\\ \sf \longmapsto B^2=75[/tex]
[tex]\\ \sf \longmapsto B=\sqrt{75}[/tex]
[tex]\\ \sf \longmapsto B=\sqrt{25\times 3}[/tex]
[tex]\\ \sf \longmapsto B=5\sqrt{3}[/tex]
[tex]\\ \sf \longmapsto B=5\times 1.732[/tex]
[tex]\\ \sf \longmapsto B=8.66[/tex]
[tex]\\ \sf \longmapsto B\approx 8.7[/tex]