Question

Find AD in the following figure:

(a) 3 cm

(b) 4 cm

(c) 5 cm

(d) 2.4 cm​

Answer 1

Answer:

(d) 2.4cm

Step-by-step explanation:

AB=3cm

AC=4cm

BC=5cm

semi perimeter= a+b+c/2

=3+4+5/2

=12/2

= 6

Area of triangle = √s(s-a)(s-b)(s-c)

=√6×3×2×1

= √3×2×3×2

= 3×2

=6 cm²

Area of triangle =1/2×AD×BC

6cm² = 1/2×AD×5

AD = 6×2/5

AD = 12/5

AD = 2.4 cm

Answer 2

Answer:

correct answer is option (d) 2.4 cm

Step-by-step explanation:

Given in ΔABC ⇒ AB = 3 cm

                         ⇒ BC = 5 cm

                         ⇒ AB = 3 cm

if we see angle at A is 90° so the given triangle is a right angle triangle

 and here AB  is base and AC perpendicular

     area Δ ABC =  $\frac{1}{2}$ × base × Perpendicular

                          = $\frac{1}{2}$ ×3 ×4 = 3× 2 = 6 $cm^{2}$

Again if take BC as base then area of triangle = $\frac{1}{2}$ ×BC ×AD

⇒ area of triangle 6 $cm^{2}$ = $\frac{1}{2}$ × 5 × AD

⇒ 6 = $\frac{5}{2}$ × AD

⇒ AD =  6 ×$\frac{2}{5}$

⇒ AD = 12/5 = 2.4 cm

the correct answer is (d) 2.4 cm