All categories

2 years ago

Please help need quickly

Mathematics

1 answer:

tensa zangetsu [6.8K]2 years ago

6 0

Answer:

area of pentagon is 172.05in²

and area of octagon 309.02 cm²

You might be interested in

Evaluate S5 for 300 + 150 + 75 + … and select the correct answer below. 18.75 93.75 581.25 145.3125

Savatey [412]

we have that

$300 + 150 + 75 +...$

Let

$a1=300\\ a2=150\\ a3=75$

we know that

$\frac{a2}{a1} =\frac{150}{300} \\\\ \frac{a2}{a1}=0.5 \\ \\ a2=a1*0.50$

$\frac{a3}{a2} =\frac{75}{150} \\\\ \frac{a3}{a2}=0.5 \\ \\ a3=a2*0.50$

$a(n+1)=an*0.50$

Is a geometric sequence

Find the value of $a4$

$a(4)=a3*0.50$

$a(4)=75*0.50$

$a(4)=37.5$

Find the value of $a5$

$a(5)=a4*0.50$

$a(5)=37.5*0.50$

$a(5)=18.75$

Find $S5$

$S5=a1+a2+a3+a4+a5\\ S5=300+150+75+37.5+18.75\\ S5=581.25$

therefore

the answer is

$581.25$

Alternative Method

Applying the formula

$S_n=\frac{a_1 (1-r^n)}{1-r} \\\\a_1=300 \\ r=\frac{1}{2}\\\\ S_5=\frac{300(1-(\frac{1}{2})^5)}{1-\frac{1}{2}}\\\\=\frac{300(1-\frac{1}{32})}{\frac{1}{2}}\\\\=\frac{300 \times \frac{31}{32}}{\frac{1}{2}}\\\\=\frac{75 \times \frac{31}{8}}{\frac{1}{2}}\\\\=\frac{\frac{2325}{8}}{\frac{1}{2}}\\\\=\frac{2325}{8} \times 2\\\\=\frac{2325}{4}\\\\=581 \frac{1}{4}\\\\=581.25$

therefore

the answer is

$581.25$

6 0

2 years ago

Read 2 more answers

Depth: 1.8 m Width: 2.5 m Height: 2 m What is the cuboid's volume?

8090 [49]

Answer:

9 m³

Step-by-step explanation:

The formula for calculating the volume (V) of a cuboid is

V = depth × width × height

= 1.8 × 2.5 × 2 = 9 m³

5 0

2 years ago

Read 2 more answers

Hi could someone just help me with this I'm not sure if i'm doing it correctly.

salantis [7]

Two angles are supplementary when they <span>add up to 180 degrees </span>⇒
m∠1 + m∠2 = 180°
4y + 7 + 9y + 4 = 180
13y + 11 = 180
13y = 180 - 11
13y = 169
y = 169/13
y = 13

m∠2 = 9y + 4 = 9 * 13 + 4 = 121°

4 0

2 years ago

The angles formed by two perpendicular lines have a measure of _______.

Tpy6a [65]

The answer is 90 degrees. SO it would be B

7 0

2 years ago

Read 2 more answers

Find the area of a circular sector in cm² with angle 15° if the length of the intercepted arc is pi/2 cm

UkoKoshka [18]

Answer:

0.52cm2

Step-by-step explanation:

l of Arc =tita/360×2πr

15/360×2×22/7×2

3 0

1 year ago