All categories

2 years ago

What is the surface area of the regular pyramid given below ?

Mathematics

2 answers:

Levart [38]2 years ago

5 0

Answer:

Option C $207\ units^{2}$

Step-by-step explanation:

we know that

the surface area of a pyramid is equal to

$SA=B+LA$

where

B is the area of the base

LA is the lateral area

The area of the base B is

$B=9*9=81\ units^{2}$

The lateral area is equal to

$LA=4*(1/2)(9*7)=126\ units^{2}$

the surface area is equal to

$SA=81+126=207\ units^{2}$

vitfil [10]2 years ago

4 0

Answer:

Choice C is correct answer.

Step-by-step explanation:

We have to find the surface area of of regular pyramid.

From given diagram , we observe that

Base = 9 units height = 7 units

The formula for total surface area of pyramid is

T.S.A = L.S.A + B

Total surface area of regular pyramid is sum of Lateral surface area and area of base.

L.S.A = 1/2pl where p is perimeter and l is height.

B = s² is area of base where s is base.

Hence, T.S.A = 1/2pl+ s²

Firstly, we have to find the perimeter.

p = 4s

p = 4(9) = 36 units

T.S.A = 1/2(36)(7)+(9)²

T.S.A = (18)(7) + 81

T.S.A = 126+81

T.S.A = 207 units.

Hence, the surface area of regular pyramid of 207 units.

You might be interested in

Isoke is solving the quadratic equation by completing the square.10x2 + 40x – 13 = 0 10x2 + 40x = 13 A(x2 + 4x) = 13What is the

Elina [12.6K]

we have

$10x^{2} + 40x - 13 = 0$

Group terms that contain the same variable, and move the constant to the opposite side of the equation

$10x^{2} + 40x =13$

Factor the leading coefficient

$10(x^{2} + 4x) =13$ ----------> the value of A is $10$

Complete the square. Remember to balance the equation by adding the same constants to each side

$10(x^{2} + 4x+4) =13+40$

$10(x^{2} + 4x+4) =53$

Rewrite as perfect squares

$10(x+2)^{2} =53$

$10(x+2)^{2} =53 \\ (x+2)^{2} =\frac{53}{10} \\ \\ x+2=(+/-)\sqrt{\frac{53}{10}} \\ \\ x1=-2+\sqrt{\frac{53}{10}}\\ \\ x2=-2-\sqrt{\frac{53}{10}}$

therefore

the answer is

the value of A is $10$

3 0

2 years ago

Read 2 more answers

-6(2r +8)=-10(r-3)<br> I need the work to

barxatty [35]

Answer:

r = -39

Step-by-step explanation:

So we are trying to solve the equation for r.

-6(2r + 8) = -10(r - 3)

Divide both sides by -2. (This will make distributing much easier.)

3(2r + 8) = 5(r - 3)

Distribute the 3 on the left side and the 5 on the right side,

6r + 24 = 5r - 15

Subtract 24 from both sides.

6r = 5r - 39

Subtract 5r from both sides.

r = -39

So now we have solve the equation.

I hope you find my answer and explanation to be helpful. Happy studying. :)

5 0

2 years ago

There are 365 days in a year and 24 hours in a day. An airport camera records for 18 hours and then automatically resets itself

likoan [24]

The answer is 486.6

There are 8,760 hours in a year, so 18 divided by 8,760 would = 486.6

5 0

2 years ago

Read 2 more answers

When alice completes each level in her favorite video game she wins 3 extra lives and 6 gold coins

Nataly_w [17]

The answer is 24. because you multiply 8 and 6 <span />

5 0

2 years ago

Read 2 more answers

Three right triangles surround a shaded triangle; together they form a rectangle measuring 12 units by 14 units. The figure belo

Alchen [17]

Answer:

its not a right angled triangle

Step-by-step explanation:

this is because it doesnt follow the rule of pytagorous theorem

7 0

2 years ago