Okay, recall the formula of these two shapes.
Area of the triangle = bh/2
where b = base, h = height
Area of the circle = π(d²/4)
where d = diameter, π ≈ 3.14
Given b = 8, h = 7, the area of the triangle is
(8*7)/2 = 28
Given d = 3, the area of the circle is
(3.14)(3²/4) = 7.065
On the figure, the triangle has a hole so that area of it is reduced so the triangle with hole is
28 - 7.065 = 20.935 (answer)
