The radius of the circle is 15 cm,
The diameter of the circle is 30 cm,
The circumference of the circle is 94.248 cm,
The area of the circle is 706.86 cm^2
The radius is given in the diagram as half the circle, which is 15 cm.
The diameter is double the radius because the diameter measures the circle from edge to edge, so 15•2=30 cm.
The circumference of the circle is 2•3.14•r=C,
2•3.14=6.28, 6.28•15= 94.248 cm.
The area of the circle is 3.14•r^2, so the radius squared is 225 (15•15) and 225•3.14=706.86 cm squared :)
Option D. 2(n + 9) is the right answer
Step-by-step explanation:
The word problems are converted into mathematical problems to solve simply.
for the given problem
"two times the sum of a number and 9"
Let n be a number then
when there is and between two things they are performed first then next operation is performed so
the sum of a number and 9

Then
two times the sum of a number and 9

Hence,
Option D. 2(n + 9) is the right answer
Keywords: Mathematical notation
Learn more about mathematical notation at:
#LearnwithBrainly
Answer to Problem 1: 5√3
Answer to Problem 2: 21√5
Area of square =6*6= 36 cm^2
Area of trapezoid =1/2( base1+base2)*height
base 1=7
base2=21-6=15
height=6
Area of trapezoid =1/2( 7+15)*6= 66
whole area = area of square + area of trapezoid= 36+66=102
Answer 102