Question

y wants to put a fence around an area. the fence will follow the diagram of the triangle shown below.
about how much fencing does molly need?
a 28 ft
b 38 ft
c 43 ft
d 49 ft

Explanation:

Step1: Identify triangle type

It's a right - triangle (has a right - angle symbol). We know two sides: one leg is 10 ft, the hypotenuse is 18 ft. We need to find the other leg first using the Pythagorean theorem $a^{2}+b^{2}=c^{2}$, where $c$ is the hypotenuse, and $a,b$ are the legs. Let the unknown leg be $x$. So $x^{2}+10^{2}=18^{2}$.

Step2: Calculate the unknown leg

$x^{2}=18^{2}-10^{2}=324 - 100 = 224$. Then $x=\sqrt{224}\approx14.97\approx15$ ft (we can also use a better approximation or just calculate the perimeter with the approximate value).

Step3: Calculate the perimeter

The perimeter of a triangle is the sum of its three sides. So perimeter $P = 10+18 + 15=43$ ft (the slight difference in approximation won't change the fact that it's closest to 43 ft).

Answer:

C. 43 ft