Answer:
[tex]\mathsf{\dfrac12(7 \ ft)(4 \ ft)}[/tex]
Step-by-step explanation:
Area of a triangle = 1/2 x base x height
⇒ area of triangle = 1/2 x 7 x 4
Therefore, Dena is correct
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Another method would be to calculate the area of the larger triangle (with base 7 ft + 3 ft) and then subtract the area of the smaller right triangle (with base 3ft), but this will give you the same answer:
area = [1/2 x (7 + 3) x 4] - [1/2 x 3 x 4) = 1/2 x 7 x 4
