The ratio of OC to OA is OC/ 10√2 - OC
<u>Explanation:</u>
Given -
AD = 4 cm
M is the midpoint of CD
Ratio of OC to OA = ?
In a square, all the interior angles are 90°
Therefore,
ΔADC, ΔABC and ΔBCM are right angled triangle
AC is the diagonal which divides ∠DAB and ∠DCB equally
If AD = 4 cm, then AB, BC and DC are also 4cm
In ΔADC,
(AC)² = (AD)² + (DC)²
(AC)² = (10)² + (10)²
AC = 10√2 cm
AC = OA + OC
OA = AC - OC
OC/OA = OC / AC - OC
OC / OA = OC / 10√2 - OC
Therefore, the ratio of OC to OA is OC/ 10√2 - OC
Answer:
95-27.50= 67.50 inches of ribbon
The dimensions of the bottom of the drawer are:
20 cm × 40 cm
So the area is : 800 cm² (rectangular shaped)
The area formula of a circle is:

r²
The diameter of the plate is 20cm
so the radius is half the diameter which is 10cm
Apply the given to the formula:

(10)²
100

314.16 cm²
2 plates in the bottom drawer
Area of two plates:
2 × 314.16
628.32 cm²
Area of the non-covered space in the bottom drawer:
Area of drawer - area of two plates
800 - 628.32
171.68 cm²
Its 75 miles per hour hope you understand