Question

7. In Fig. 21. ABCD is a parallelogram, DL is perpendicular to AB. If AB = 20 cm, AD = 13 cm and area of the
parallelogram is 100 cm, find AL.​

Answer 1

Answer:

12cm

Step-by-step explanation:

area of parallelogram = base * altitude = 100 cm^2

taking AB as base and DL as altitude

100 = 20 * DL

DL = 5cm

in right triangle ADL

AD^2 = AL^2 + DL^2

(13)^2 = AL^2 + 5^2

169 = AL^2 + 25

AL^2 = 144

AL = 12cm