Question

Unit4: Congruent Triangles Hw 1: Classifying Triangles Gina Wilson (All things algebra) 2014

Answer 1

Answer:

• 12. x = 6, side = 83
• 13. x = 18, side = 29
• 14. x = 11, sides = 74, 74 and 37
• 15. x = 23, sides = 95, 95 and 108

Step-by-step explanation:

11 is incomplete, can't solve

12

The triangle is equilateral, so all sides are equal, using one pair to find x:

• 13x + 5 = 17x - 19
• 17x - 13x = 5 + 19
• 4x = 24
• x = 6

Each side is:

• 13*6 + 5 = 78 + 5 = 83

13.

Sides are equal as triangle is equilateral

• QR = 2x - 7
• RS = 5x - 61
• QS = x + 11

Finding x by comparing two sides

• 2x - 7 = 5x - 61
• 5x - 2x = 61 - 7
• 3x = 54
• x = 18

Sides are equal

• 18 + 11 = 29

14.

Equal sides of isosceles triangle:

• CD = DE
• 9x - 25 = 6x + 8
• 9x - 6x = 8 + 25
• 3x = 33
• x = 11

Sides are

• CD = DE = 9*11 - 25 = 99 - 25 = 74
• CE = 10*11 - 73 = 110 - 73 = 37

15.

Equal sides of isosceles triangle WXY, WX = WY

• WX = 4x + 3
• WY = 7x - 66
• XY = 5x - 7
• 4x + 3 = 7x - 66
• 7x - 4x = 3 + 66
• 3x = 69
• x = 23

Sides are:

• WX=WY = 4*23 + 3 = 95
• XY = 5*23 - 7 = 108

Answer 2

Answer:

11. Isosceles

Step-by-step explanation:

DE = √(-2-5)^2 +(3-5)^2  =  √(-7)^2 + (-2)^2  =  √49+4 =  √53

DF = √(-2+4)^2 + (3-10)^2  =  √(2)^2 + (-7)^2  =  √4+49  =  √53

EF =  √(5+4)^2 + (5-10)^2  =  √(9)2 + (-5)^2  =  √81+25  =  √106