Given: △abc is an isosceles triangle, ac - base △bdc is an equilateral triangle perimeter of △abc = 42, ac = 12 find: perimeter of △bdc

Perimeter of △BDC=Sum of all the sides=BD+DC+CB=15+15+15=45

Step-by-step explanation:

Given ΔABC is an isosceles triangle, thus, AB=BC=x and AC=12,

perimeter of  △ABC is=42

⇒x+x+12=42

⇒2x=30

⇒x=15

Thus, AB=BC=15

Now, △BDC is an equilateral triangle therefore BD=DC=BC=x

Since, x=15, therefore BD=DC=BC=15

Now, Perimeter of △BDC=Sum of all the sides=BD+DC+CB=15+15+15=45

The perimeter is 45 cm

Step-by-step explanation:

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c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.

triangle and cube

step-by-step explanation: