What is the radius of a sphere which area is equal to the sum of the areas of four circles of radius 7?

radius = 7 units

Step-by-step explanation:

Given:

Radius = 7 units

Find area of 4 circles:

1 circle = π (7)² = 49π units²

4 circles = 49π x 4 = 196π units²

Find radius of sphere:

4πr²  = 196π

r² = 49

r = 7

option a, c,d are correct.

step-by-step explanation:

from the given figure, it is given that z is equidistant from the sides of the triangle rst, then from triangle tzb and triangle szb, we have

tz=sz(given)

bz=zb(common)

therefore, by rhs rule,δtzb ≅δszb

by cpctc, sz≅tz

also, from δctz and δasz,

tz=sz(given)

∠tcz=∠saz(90°)

by rhs rule, δctz ≅ δasz, therefore by cpctc, ∠ctz≅∠asz

also,from δasz and δzsb,

zs=sz(common)

∠zbs=∠saz=90°

by rhs rule, δasz ≅δzsb, therefore, by cpctc, ∠asz≅∠zsb

hence, option a, c,d are correct.