In a regular triangular pyramid SABC, Q is the middle of the edge AB, S is the apex.
| September 24, 2021 | education
In a regular triangular pyramid SABC, Q is the middle of the edge AB, S is the apex. It is known that SQ = 28, and the lateral surface area is 294. Find the length of the segment BC.
Since point M is the midpoint of the edge BC, the segment SQ is the median of the side face SBC. Since the side face of a regular pyramid is an equilateral triangle, the median SQ is also its height.
The side faces of the regular pyramid are equal, then Sside = 3 * Ssвс.
Ssvs = 294/3 = 98 cm2.
The area of the side facet SBC is equal to: Ssвс = BC * SQ / 2 = 98.
ВС = Ssвс * 2 / SQ = 98 * 2/28 = 7 cm
Answer: The length of the BC segment is 7 cm.
One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.
