What is diameterof the circle if the area of the circle is78.5cm

1.	What is diameterof the circle if the area of the circle is78.5cm
Answer» ONG>Given :- Area of circle = 78.5 cm² To Find :- The diameter of circle = ? ANSWER :- The diameter of circle = 10 cm Explaination :- Let 'r' be the radius of the Circle. ★ According to Question :- → Area of circle = πr² Taking π = 3.14 we GET : → 78.5 = 3.14 × r² → r² = 78.5 ÷ 3.14 → r² = 25 Taking square root to the both sides we get : → r = √25 → r = 5 cm Now, As we know that, → Diameter = 2 × Radius SUBSTITUTING the value of r in above formula : → Diameter = 2 × 5 → Diameter = 10 cm Hence, The diameter of circle is 10 cm. __________________ Extra Shots :- Volume of cylinder = πr²h T.S.A of cylinder = 2πrh + 2πr² Volume of cone = ⅓ πr²h C.S.A of cone = πrl T.S.A of cone = πrl + πr² Volume of cuboid = l × b × h C.S.A of cuboid = 2(l + b)h T.S.A of cuboid = 2(lb + bh + lh) C.S.A of cube = 4a² T.S.A of cube = 6a² Volume of cube = a³ Volume of sphere = 4/3πr³ Surface area of sphere = 4πr² Volume of hemisphere = ⅔ πr³ C.S.A of hemisphere = 2πr² T.S.A of hemisphere = 3πr²

Answer» ONG>Given :-

To Find :-

ANSWER :-

Explaination :-

★ According to Question :-

→ Area of circle = πr²

→ 78.5 = 3.14 × r²

→ r² = 78.5 ÷ 3.14

→ r² = 25

Taking square root to the both sides we get :

→ r = √25

→ r = 5 cm

Now,

As we know that,

→ Diameter = 2 × Radius

SUBSTITUTING the value of r in above formula :

→ Diameter = 2 × 5

→ Diameter = 10 cm

Hence,

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