Question

PLEASE DO THESE FIRST ONE TO DO THEM WILL BE RATED 5 AND THANKED AND I WILL MAKE HIM BRAINLLEST AND YOU WILL GET 50 POINTS OR MORE THANK YOU

Answer 1

☯ AnSwErS :

(1). a

We know the formula to calculate area of semi - circle.

$\Large{\implies{\boxed{\boxed{\sf{Area = \frac{\pi r^2}{2} }}}}}$

Where, Radius = 4.5 cm

★ Putting Values ★

$\sf{\dashrightarrow Area = \frac{\pi (4.5)^2}{2}} \\ \\ \sf{\dashrightarrow Area = \frac{20.25 \pi}{2}} \\ \\ \sf{\dashrightarrow Area = \frac{20.25 \times \frac{22}{7} }{2}} \\ \\ \sf{\dashrightarrow Area = \frac{ \frac{445.5}{7} }{2}} \\ \\ \sf{\dashrightarrow Area = \frac{445.5}{7 \times 2}} \\ \\ \sf{\dashrightarrow Area = 31.82} \\ \\ \Large{\implies{\boxed{\boxed{\sf{Area = 31.82 \: cm^2}}}}}$

$\rule{200}{2}$

(b).

We know the formula to calculate area of semi - circle.

$\Large{\implies{\boxed{\boxed{\sf{Area = \frac{\pi r^2}{2} }}}}}$

Where, Radius = 6.5 cm

★ Putting Values ★

$\sf{\dashrightarrow Area = \frac{\pi (6.5)^2}{2}} \\ \\ \sf{\dashrightarrow Area = \frac{42.25 \pi}{2}} \\ \\ \sf{\dashrightarrow Area = \frac{42.25 \times \frac{22}{7} }{2}} \\ \\ \sf{\dashrightarrow Area = \frac{ \frac{929.5}{7} }{2}} \\ \\ \sf{\dashrightarrow Area = \frac{929.5}{7 \times 2}} \\ \\ \sf{\dashrightarrow Area = 66.39} \\ \\ \Large{\implies{\boxed{\boxed{\sf{Area = 66.39 \: cm^2}}}}}$

$\rule{200}{2}$

(c).

We know the formula to calculate area of semi - circle.

$\Large{\implies{\boxed{\boxed{\sf{Area = \frac{\pi r^2}{2} }}}}}$

Where, Radius = 3 cm

★ Putting Values ★

$\sf{\dashrightarrow Area = \frac{\pi (3)^2}{2}} \\ \\ \sf{\dashrightarrow Area = \frac{9 \pi}{2}} \\ \\ \sf{\dashrightarrow Area = \frac{9 \times \frac{22}{7} }{2}} \\ \\ \sf{\dashrightarrow Area = \frac{ \frac{198}{7} }{2}} \\ \\ \sf{\dashrightarrow Area = \frac{198}{7 \times 2}} \\ \\ \sf{\dashrightarrow Area = 14.14} \\ \\ \Large{\implies{\boxed{\boxed{\sf{Area = 14.14 \: cm^2}}}}}$

$\rule{200}{2}$

(d).

We know the formula to calculate area of semi - circle.

$\Large{\implies{\boxed{\boxed{\sf{Area = \frac{\pi r^2}{2} }}}}}$

Where, Radius = 12 cm

★ Putting Values ★

$\sf{\dashrightarrow Area = \frac{\pi (12)^2}{2}} \\ \\ \sf{\dashrightarrow Area = \frac{144 \pi}{2}} \\ \\ \sf{\dashrightarrow Area = \frac{144 \times \frac{22}{7} }{2}} \\ \\ \sf{\dashrightarrow Area = \frac{ \frac{3168}{7} }{2}} \\ \\ \sf{\dashrightarrow Area = \frac{3168}{7 \times 2}} \\ \\ \sf{\dashrightarrow Area = 226.28} \\ \\ \Large{\implies{\boxed{\boxed{\sf{Area = 226.28 \: cm^2}}}}}$

$\rule{200}{2}$

(2). (a)

We know the formula to calculate area of quadrant of the circle.

$\Large{\implies{\boxed{\boxed{\sf{Area = \frac{\pi r^2}{4} }}}}}$

Where, Radius = 8 cm

★ Putting Values ★

$\sf{\dashrightarrow Area = \frac{\pi (8)^2}{4}} \\ \\ \sf{\dashrightarrow Area = \frac{64 \pi}{4}} \\ \\ \sf{\dashrightarrow Area = \frac{64 \times \frac{22}{7} }{4}} \\ \\ \sf{\dashrightarrow Area = \frac{ \frac{1408}{7} }{4}} \\ \\ \sf{\dashrightarrow Area = \frac{1408}{7 \times 4}} \\ \\ \sf{\dashrightarrow Area = 50.28} \\ \\ \Large{\implies{\boxed{\boxed{\sf{Area = 50.28 \: cm^2}}}}}$

$\rule{200}{2}$

(b).

As, we have to find the radius of cylinder.

Where, Height = 14 cm

$\Large{\implies{\boxed{\boxed{\sf{Volume = \pi r^2 h}}}}}$

★ Putting Values ★

$\sf{\dashrightarrow 1360 = \frac{22}{\cancel{7}} \times r^2 \times \cancel{14}} \\ \\ \sf{\dashrightarrow 1360 = 44 \times r^2} \\ \\ \sf{\dashrightarrow r^2 = \frac{1360}{44}} \\ \\ \sf{\dashrightarrow r^2 = 30.9} \\ \\ \sf{\dashrightarrow r = \sqrt{30.9}} \\ \\ \sf{\dashrightarrow r = 5.55} \\ \\ \Large{\implies{\boxed{\boxed{\sf{r = 5.55 \: cm}}}}}$

Answer 2

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