13. 81.64
14. 803.84
15. 153.83
16. 753.6
you just use circumference and area formulas for a circle
Rectangle: a = w x l
Square: a = a^2
Triangle: a= b x h divided by 2
Parallelogram: a = HH
Trapezoid: a = a+b
2h
Answer:
20°
Step-by-step explanation:
40°, 70° and 90° are the measures of the three angles of the quadrilateral.
Measure of fourth angle of the Quadrilateral
= 360° - (40° + 70° + 90°)
= 360° - 200°
= 160°
Measure of angle 1 will be equal to the measure of the linear pair angle of 160° as they are corresponding angles.
Thus,


Alternate method:
![m\angle 1 = 180\degree- [360\degree-(40\degree+70\degree+90\degree)]](https://tex.z-dn.net/?f=m%5Cangle%201%20%3D%20180%5Cdegree-%20%5B360%5Cdegree-%2840%5Cdegree%2B70%5Cdegree%2B90%5Cdegree%29%5D)
![\implies m\angle 1 = 180\degree- [360\degree-200\degree]](https://tex.z-dn.net/?f=%5Cimplies%20m%5Cangle%201%20%3D%20180%5Cdegree-%20%5B360%5Cdegree-200%5Cdegree%5D)


Answer:
-10,10
Step-by-step explanation:
The given quadratic equation is

The discriminant of this equation is given by;

where a=k, b=20, c=k
For rational solutions, the discriminant must be zero.

Simplify to get:

This implies that:


Take square root to get:



Answer:
8 cm
Step-by-step explanation:
... BO/OD = AO/OC = 3/1
Written another way, this is ...
... OD : BO = 1 : 3
Now, BD = OD + BO, so we have
... BD : BO = (OD +BO) : BO = (1 +3) : 3 = 4 : 3
That is, BD = 4/3 × BO
... BD = 4/3 × 6 cm = 8 cm