Explanation

• Let r be the radius of a circle.
• Then, the area of the circle = πr^2 
• If radii are doubled, than radii become 2r.
• Now, area of circle =π(2r) 2
•  =4π.
• Therefore, the area of the circle is increased by 4 times.

Explanation

Mean = Sum of values ÷ Number of values
= (10 + 20 + 30) ÷ 3

= 60 ÷ 3

= 20.

Last updated by NA on 09-09-2026

Explanation

The three interior angles of every triangle always add up to 180 degrees

Basic Geometry Formulas

Triangle

• Area = ½ × Base × Height
• Perimeter = a + b + c
• Sum of angles = 180°

Rectangle

• Area = Length × Width
• Perimeter = 2(Length + Width)

Square

• Area = Side²
• Perimeter = 4 × Side

Circle

• Area = πr²
• Circumference = 2πr

Triangle angle

• Interior angles = 180°

Last updated by NA on 09-09-2026

Explanation

At 3:00, the minute hand is at 12 and the hour hand is at 3.

The angle between them is 90° (a right angle).

Last verified on 07-09-2026

Explanation

Given:

Sum of 14 values = 168

Number of values = 14

Formula:

Mean = Sum ÷ Number of values

Mean = 168 ÷ 14 = 12