Question

Can someone please help me I really need help please help me

Answer 1

(44 - 8(pi)) cm^2 Exact area

18,9 cm^2 Approximate area

Explanation:

The shaded area is the area of the trapezoid minus the area of the semicircle.

area of trapezoid = (b1 + b2)h/2

area of semicircle = (pi)(r^2)/2

The triangles at both sides are right triangles. Each of the horizontal legs has length (14 cm - 8 cm)/2 = 3 cm. Each of the vertical legs is congruent to the radius of the semicircle.

b1 = lower base = 14 cm

b2 = upper base = 14 cm - 3 cm - 3 cm = 8 cm

shaded area = (b1 + b2)h/2 - (pi)(r^2)/2

= (14 cm + 8 cm)(4 cm)/2 - (pi)(4 cm)^2 / 2

= 44 cm^2 - 8(pi) cm^2

= (44 - 8(pi)) cm^2 Exact area

= 18.9 cm^2 Approximate area

Answer 2

18.87 square cm.

Explanation:

The area of the rectangle will be (4 + 4) * 4, since the length of the rectangle would be the diameter of the circle, and the width of the rectangle would be the radius. (4 + 4) * 4 = 8 * 4 = 32 square cm.

Then, we can calculate the area of the semicircle. The area of a circle is pi * r^2, so the area of a semicircle will be half of that. pi * (4^2) / 2 = pi * 16 / 2 = 8pi. 8 * 3.14159265 = 25.1327412 square cm.

The shaded area of the middle of the shape will then be 32 - 25.1327412 = 6.8672588 square cm.

The two triangles will have the same area. Their bases will be 14 minus the diameter of the circle, then divide that by 2 to get each separate base. 14 - 8 = 6 / 2 = 3. The heights of the triangles will be the radius of the circle, or 4 cm.

1/2 * 3 * 4 = 1/2 * 12 = 12/2 = 6. That is the area of one triangle, so the area of both triangles would be 6 * 2 = 12 square cm.

6.8672588 + 12 = 18.8672588, or 18.87 square cm.

Hope this helps!