Question

triangle ABC right angled at A (fig 11.25).AD is perpendicular to BC. If AB = 5cm, BC = 13 cm, AC = 12cm, find the area of triangle ABC. Also find the length of AD.​

Answer 1

Answer:

AD = 4.6 cm (approx.)

Step-by-step explanation:

in Δ ABC, right angles at A

base (AB) = 5 cm

height (AC) = 12 cm

arΔ ABC = 1/2* base * height            (as ABC is right angled triangle at A)

               = $\frac{1}{2} *5*12$

               = 5*6

               = 30 cm²

now, AD is a ⊥ on BC in ΔABC

=> base (BC) =13 cm

    Height (AD) = x cm   (let it be x)

∴ arΔ ABC = $\frac{1}{2} *13*x$

           30 = $\frac{1}{2} *13*x$

           $\frac{30*2}{13} =x\\\\\frac{60}{13} = x$

            x = 4.615 cm or 4.6 cm (approx.)