What is the area of the rectangle? 40 units² 45 units² 50 units² 55 units²

see the attached figure with letters to better understand the problem

we know that

If the figure is a rectangle          

then

The area of the rectangle is equal to

where  

B is the base  

h is the height  

the base B is equal to the distance AB

the height h is equal to the distance AD  

Step 1

Find the distance AB

the formula to calculate the distance between two points is equal to

substitute the values

Step 2

Find the distance AD

the formula to calculate the distance between two points is equal to

substitute the values

Step 3

Find the area of the rectangle

we have

substitute

therefore

the answer is the option

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this