Answer:
[tex]\frac{1}{3}[/tex]
Step-by-step explanation:
Calculate the total area of the rectangle:
21 x 12 = 252
Half of the rectangle is unshaded so:
252 ÷ 2 = 126
For clarification, side A is the top, side B is the left hand side and side C is the bottom.
Now, find the area of the unshaded side of the other triangle. As the length of side C is 21 and the shape is a rectangle, side A is also 21. We need to calculate the amount is unshaded on this side so:
21 - 14 = 7
(7 x 12) ÷ 2 = unshaded
84 ÷ 2 = 42
So now we know the total of the shape that is shaded, we can now subtract this from the total area of the shape:
252 - 126- 42 = 84
Which in fraction form is:
[tex]\frac{84}{252}[/tex]
This can be simplified down by dividing both the numerator and the denominator by 3:
[tex]\frac{84 \div 3}{252 \div 3}[/tex]
=[tex]\frac{1}{3}[/tex]
Hope this helps!
