contestada

In Isosceles trapezoid ABCD, the longer base, AB, is one and one half times as long as the shorter base, CD. The other two sides, AD and BC, are both 13 cm. long. a. If the perimeter is 76 cm. find the lengths of AB and CD. b. If the height of the trapezoid is 12 cm. find its area. (Hint: Area

Respuesta :

otal perimeter = 76cm = AB + BC + CD + AD

AD & BC = 13cm

AB = 1.5*(CD)

Solution:

Since we know AD & BC are both 13cm long, plug those numbers into the perimeter equation

76cm+=+AB+%2B+BC+%2B+CD+%2B+AD Place 13cm in for AD & BC

 

76cm+=+AB+%2B+13cm+%2B+CD+%2B+13cm Combine like terms

76cm+=+AB+%2B+CD+%2B+26cmSubtract 26cm from both sides

50cm+=+AB+%2B+CD Now it is time to substitute the 1.5*(CD) for AB

50cm+=+1.5%2A%28CD%29+%2B+CD rewrite the equation

50cm+=+2.5%2A%28CD%29 Divide both sides by 2.5

20cm+=+CD

To find AB, plug 20cm in for CD in the equation AB = 1.5*(CD)

AB+=+1.5%2A20cm

AB+=+30cm

Otras preguntas