It's an isosceles triangle because base angles are same( 45°).
1 meter = 1,000 millimeter
We can solve this by making two proportion or millimeter over meter: 

Now you must solve for the unknown meter under the first proportion:
(1,000)(x meter) = 19.5 * 1
1,000(x meter) = 19.5
x meter = 0.0195 m
19.5 mm = 0.0195 m
Hope this helped! Let me know if you have any further questions
~ Just a girl in love with Shawn Mendes
Answer:

Step-by-step explanation:
The area of the figure is equal to the area of four right triangles
so
The area of one right triangle is equal to


Multiply by 4

<em>Alternative Method</em>
The figure is a Rhombus
The area of the Rhombus is equal to

where
D1 and D2 are the diagonals of the rhombus
we have

substitute


the answer is neither because they just do look like they do but they don't because they are actually neither that's why it is so tricky.