Answer
Find out the what is the surface area of the pyramid .
To proof
Formula
Surface area of a square pyramid

Where a is the base edge and h be the height .
As given
A square pyramid has a base with side lengths each measuring 40 inches. The pyramid is 21 inches tall, with a slant height of 29 inches.
i.e Base edge = 40 inches
Height = 21 inches
Put values in the above formula

solving



= 1600 + 80 × 29
= 3920 inches²
Therefore the surface area of the pyramid is 3,920 inches²
Hence proved
Answer:
108, 108, 72
Step-by-step explanation:
Vertical angles are congruent and if the measure of 1 of the angles is 72 degrees and straight lines equal 180 degrees you have to subtract 72 from 180 which equals 108.
Answer:
4004
Step-by-step explanation:
The number of combinations of choosing r objects from a group of n is nCr.
So the number of ways to get 7, 8, 9, or 10 heads from 13 coin tosses is:
₁₃C₇ + ₁₃C₈ + ₁₃C₉ + ₁₃C₁₀
= 1716 + 1287 + 715 + 286
= 4004