So the perimeter is the measurement of the shape all around. I marked the perimeter in green.
Let's use l for the unknown side.
Since the equation to find the perimeter of a rectangle is
(p = perimeter, l = length, w = width)
p = l + l + w + w
Since w = 10, and p = 50..
50 = l + l + 10 + 10
Simplify:
50 = 2l + 20
Now let's solve:
Subtract 20 from each side.
30 = 2l
Divide by 2 on each side.
15 = l
Now that we know the length is 15, we can use this equation to find the area.
(a = area)
a = wl
Since w = 10, and l = 15...
a = 10 · 15
Solve:
a = 150
The answer is 150.
Hope this helped! If you have anymore questions or don't understand, please comment on my profile or DM me. :)
