+REP can't do this :'[

[Mitch4?]

Okay i keep coming out with 2 of the answers, and i'd really appreicaite if anyone can help me :]] Ty :'[ i cant believe i cant do it

[DiscoPat]

i think its D but not 100% sure

[Mitch4?]

Nvm i found the answer i'll explain.. :p

if the radius of the circle = r. Then the side of the large square will be X and the side of the little square be x. (0.5X)2 + (0.5X)2 = r2 = 2*0.25X2 = 0.5X2. X2 = 2r2. (0.5x)2 + x2 = r2. 1.25x2 = r2. x2 = 0.8r2. x2:X2 = 0.8r2 : 2X2 = 2:5.

[tularis]

The answer is B

- The square in a half circle / The square in the full circle
- Half of the circle is 0.5, the smaller square is at a ratio of 0.5

Answer: 1:2

[Jesus-Egg]

The answer is C, 2:5

The small square:


r is the radius of the circle

Finding angle θ:
tan θ = 2/1
θ = tanֿ¹ 2
θ = 63.4º (3sf)

Finding the length 2a in terms of r:
sin 63.4 = 2a / r
2a = r sin 63.4
2a = 0.894 r

Area of square:
Area = (0.894 r)²
Area = 0.8 r²

The big square:


Finding b in terms of r:
sin 45 = b / r
b = r sin 45
b = 0.707 r

therefore 2b = 1.41 r

Area of square:
Area = (1.41 r)²
Area = 2 r²

So, the ratio is 0.8:2
= 2:5