Question

© AB - AD
LDAB = 90°
(3 ③ AB=AD and LDAB = 90°​

Answer 1

Answer:

70 cm

Step-by-step explanation:

Let the triangle be ABC in which Angle B = 90 Degree Thus it is  right angle triangle

When we draw a perpendicular BD on Side AC of the triangle, side AC gets divided into two equal parts,

Thus AD = DC

 

Now, we are Given that, AB = 20 Cm

                                      BD = 14.5 Cm

Since Angle B is 90 Degree when we draw a perpendicular from angle B Then,       Angle ABD = Angle DBC = 45 Degree

Now in triangle ABD,           Tan 45 = AD / BD

putting the value of BD,        Tan 45 = AD / 14.5

                                                 1 = AD / 14.5

Thus, AD = DC = 14.5 Cm

Therefore Side AC = AD + DC = 14.5 + 14.5 =29 Cm

Now by Pythagoras Theorem,  In triangle ABC,

               

                                    AB^2 +BC^2 = AC^2

                                       20^2 + BC^2 = 29^2

                                               BC^2 = 841 - 400

                                               BC^2 = 441

                                               Thus, BC = 21 Cm

Now Area of Triangle ABC = 1/2 * AB * BC

                                    Area = 0.5 * 20 * 21

                                    Area = 210 Cm Sqr

         

and                    Perimeter = Ab + BC + AC  

                                          = 20 +21 + 29

                                          = 70 Cm