Answer:
The length of EF = x = 18 cm
Option A is correct.
Step-by-step explanation:
Ware given perimeter of triangle = 97 cm
We need to find length of EF = x = ?
The length of EG = x+7
The length of EF = x
The length of GF = 3x
The formula used is: 
Putting values and finding x i.e length of EF
So, value of x=18 cm
The length of EF = x = 18 cm
Option A is correct.
The value of the angles should be. (x-40°). , (x-20°), (½x-10°) , not (x-40°) + (x-20°)+(½x-10°)
Sum of all the interior angles of a triangle is 180°.
So a equation can be made by the given data,
(x-40°) + (x-20°) + (½ x-10°) = 180°
x-40°+x-20°+½x-10° = 180°
2x+½x -60°-10° = 180°
5/2 x - 70° = 180°
5/2 x = 180° + 70°
5/2 x = 250°
x = 250° × 2/5
x = 50° × 2
x = 100°
So the angles are
x-40° = 100°-40° = 60°
x-20° = 100°–20° = 80°
½x-10° = ½(100)° - 10° = 50° -10° = 40°
The answer can be checked by putting the values of the angle we got in the second statement i.e. Sum of all the interior angles of a triangle is 180°.
60° + 80° + 40° = 100° + 80° = 180°
Well, we dont know because we cant see the barmodels
The first portion is 2 and his speed during the cool down portion also 2 so I think it should be 2+2 which is 4
