Pqrs is a diameter of a circle of radius 6cm. the lengths pq , qr , and rs are equal .semicircles are drawn on pq and qs as diameters. find the perimeter of the shaded region ? ?

Part a) Rectangle

Part b) Triangle

Step-by-step explanation:

The picture of the question in the attached figure N 1

Part A) A cross section of the rectangular pyramid is cut with a plane parallel to the base. What is the name of the shape created by the cross section?

we know that

When a geometric plane slices any right pyramid so that the cut is parallel to the plane of the base, the cross section will have the same shape (but not the same size) as the base, So, in the case of a right rectangular pyramid, the cross section is a rectangle

Part b)  If a cross section of the rectangular pyramid is cut perpendicular to the base, passing through the top vertex, what would be the shape of the resulting cross section?

we know that

Cross sections perpendicular to the base and through the vertex will be triangles

see  the attached figure N 2 to better understand the problem