To find the value of с, we can use the formula for the perimeter of a trapezoid:
P = a + b + 2c
Given that P = 78 cm, a = 25 cm, and b = 18 cm, we can plug in the values and solve for c:
78 = 25 + 18 + 2c78 = 43 + 2c
Subtracting 43 from both sides:
35 = 2c
Dividing by 2:
c = 17.5 cm
Therefore, the value of с is 17.5 cm.
To find the value of с, we can use the formula for the perimeter of a trapezoid:
P = a + b + 2c
Given that P = 78 cm, a = 25 cm, and b = 18 cm, we can plug in the values and solve for c:
78 = 25 + 18 + 2c
78 = 43 + 2c
Subtracting 43 from both sides:
35 = 2c
Dividing by 2:
c = 17.5 cm
Therefore, the value of с is 17.5 cm.