Answer:
83.2 cm^2
Step-by-step explanation:
To solve this we're going to find the area of the bigger triangle (the shaded and unshaded parts together) and then the area of the smaller triangle (the unshaded part) and then subtract that from the area of the bigger triangle. We're going to use the equation: Area=1/2 x base x height. So the base of the big triangle is 16, and the height is (10.4+8.6 = 19). Put into the equation this looks like this: Area=1/2 x 16 x 19, so by multiplying we find that the area is 152 cm^2. Next we find the small triangle's area, Area=1/2 x 16 x 8.6, so the area is 68.8. Then to find the area of the shaded part, we subtract the unshaded area (68.8) from the whole area (152), 152-68.8=83.2.
<span>2257987 is the answer</span>
I realise this is quite late but in case you still wanted the answer, the width is 3m.
If the length is 3m longer than the width, you can write the width as x and the length as x + 3. The perimeter would be both lengths and both widths added together, so you would just write it as:
x + x + x + 3 + x + 3 = 18
4x + 6 = 18
- 6
4x = 12
÷ 4
x = 3
I hope this helps!