Given a pyramid at the base of which lies a rhombus with sides of 4 cm. Acute angles 30 °,
Given a pyramid at the base of which lies a rhombus with sides of 4 cm. Acute angles 30 °, dihedral angles at the base 45 °. Find the volume of the pyramid
Determine the area of the rhombus at the base of the pyramid through two sides and the angle between them.
Savsd = AВ * AD * SinВAD = 4 * 4 * (1/2) = 8 cm2.
Let’s define the area of the rhombus through the side and the height.
Savsd = СD * MН = 4 * MН.
Let’s equate both equations.
4 * MH = 8.
MH = 8/4 = 2 cm.
Then OH = MH / 2 = 2/2 = 1 cm.
Let’s draw the height of the CК of the side face of the pyramid.
In a right-angled triangle KAН, the KНO angle, by condition, is equal to 450, then the KAН triangle is isosceles, KO = OH = 1 cm.
Let’s define the volume of the pyramid.
V = Savsd * KO / 3 = 8 * 1/3 = 2 (2/3) cm3.
Answer: The volume of the pyramid is 2 (2/3) cm3.