Gina Wilson all things algebra unit 4 homework 3 questions 12-15

Step-by-step explanation:

the essential thing to remember here (and please, burn this into your brain for life) : the sum of all angles in a triangle is always (really always) 180 degrees.

therefore, in 12 and 13 we only need to add all 3 angles, and their sum must be 180.

from there we get really all 4 answers.

the next thing to consider is when a triangle had two equal angles, then it is an isoceles triangle (the 2 sides leading away from these 2 angles are equally long). that gives us the answers for 14 and 15.

12.

3x + 18 + 7x - 58 + 2x - 8 = 180

12x - 48 = 180

12x = 228

x = 19

angle A = 3x+18 = 3×19 + 18 = 57+18 = 75 degrees

angle B = 7x-58 = 7×19 - 58 = 133-58 = 75 degrees

angle C = 2x-8 = 2×19 - 8 = 38 - 8 = 30 degrees

13.

8x - 17 + 19x + 4 + 5x + 1 = 180

32x - 12 = 180

32x = 192

x = 6

angle Q = 8x-17 = 8×6 - 17 = 48-17 = 31 degrees

angle R = 19x+4 = 19×6 + 4 = 114+4 = 118 degrees

angle S = 5x+1 = 5×6 + 1 = 30+1 = 31 degrees

14.

KL = 9x - 14

LM = 7x - 37

KM = 3x + 23

angle K = angle L

so, the sides LM and KM must be equally long. that gives us

7x - 37 = 3x + 23

4x = 60

x = 15

KL = 9x-14 = 9×15 - 14 = 135-14 = 121

LM = 7x-37 = 7×15 - 37 = 105-37 = 68

KM = 3x+23 = 3×15 + 23 = 45+23 = 68

15.

XY = 13x - 21

YZ = 8x - 6

XZ = x + 4

angle X = angle Z

so, the sides XY and ZY (or YZ) must be equally long. that gives us

13x - 21 = 8x - 6

5x = 15

x = 3

XY = 13x-21 = 13×3 - 21 = 39-21 = 18

YZ = 8x-6 = 8×3 - 6 = 24-6 = 18

XZ = x + 4 = 3+4 = 7

deez nu tz

step-by-step explanation:

the answer is: d) o, f, and kr.

atomic radius of bromine (br) is 114 pm.

atomic radius of oxygen (o) is 73 pm.

atomic radius of fluorine (f) is 72 pm.

atomic radius of krypron (kr) is 112 pm.

the atomic radius of a chemical element is a measure of the size of its atom.

the atomic radius varies with increasing atomic number, but usually increases because of increasing of number of electrons.

the atomic radius decreases across the periods because an increasing number of protons, because greater attraction between the protons and electrons.