Question

A rectangle is cut in half along the diagonal to form a triangle. if the area of the triangle is (2x + 10) cm^2, what is the area of the rectangle? Please provide steps and reason for your answer too!

Answer 1

Since it's literally cut in half, that means the triangle's area is literally half of the rectangle's area. Therefore, if we write it as
the triangle's area (a)=(1/2)*(b) (the rectangle's area) we can multiply 2 to both sides to get 2*a=b. Since a is (2x+10), we can plug it in and use the distributive property (since we just can't add up variables and integers) to get 
2*(2x+10)=4x+20=b