Need help asap please help Find the surface area of this regular pyramid

189 ft²

Step-by-step explanation:

In the above diagram we are given

Slant height = 6ft

Base = 9 ft

The formula for the surface area of this regular pyramid is given as:

S.A = 2bs + b²

S.A = 2 × 9 × 6 + 9²

S.A = 108 + 81

S.A = 189 square feet(ft²)

the answer is: d) o, f, and kr.

atomic radius of bromine (br) is 114 pm.

atomic radius of oxygen (o) is 73 pm.

atomic radius of fluorine (f) is 72 pm.

atomic radius of krypron (kr) is 112 pm.

the atomic radius of a chemical element is a measure of the size of its atom.

the atomic radius varies with increasing atomic number, but usually increases because of increasing of number of electrons.

the atomic radius decreases across the periods because an increasing number of protons, because greater attraction between the protons and electrons.