The perimeter of the isosceles ?ABC with the base BC is equal to 40 cm. Perimeter of the equilateral ?BCD is 45 cm. Find AB and

Question

3 years ago

7

BC.

1 answer:

Juliette [100K] · Answer 1 · 2022-04-19T04:14:55+03:00

Answer: AB = 12.5, BC = 15

Step-by-step explanation:

Perimeter of ΔBCD = BC + CD + BD. Since it is an isoceles triangle, then BC = CD = BD. So, Perimeter of ΔBCD = 3BC

3BC = 45

÷3 ÷3

BC = 15

Perimeter of ΔABC = AB + BC + AC. Since it is an isosceles triangle with BC as the base, then AB = AC. So, Perimeter of ΔABC = 2AB + BC

2AB + BC = 40

2AB + 15 = 40

-15 -15

2AB = 25

÷2 ÷2

AB = 12.5