Question

ABC is a triangle, right-angled at C. If AB = 15 cm and AC = 12 cm, then BC = ____ *
1 point
9 cm
27 cm
81 cm
3 cm​

Answer 1

Step-by-step explanation:

$\purple{ \sf \: By \: using \: Pythagoras \: Theorem} \\ \sf \: {H}^{2} = {B}^{2} + {P}^{2} \\ \sf \: H = AB = 15 \: cm \\ \sf B = BC = ? \\ \sf P = AC = 12 \: cm \\ \sf ({15})^{2} = {BC}^{2} + ({12})^{2} \\ \sf \: 225 = {BC}^{2} + 144 \\ \sf{BC}^{2} = 225 - 144 \\ \sf{BC}^{2} = 81 \\ \sf \: BC = \sqrt{81} \\ \sf \: BC = 9 \: cm$

Answer 2

Given :

• ABC is a right angled Triangle in which AB = 15 cm and AC = 12 cm .

To Find :

• Length of BC .

Solution :

$\longmapsto\tt{AB=15\:cm}$

$\longmapsto\tt{AC=12\:cm}$

By Pythagoras Theorem :

$\longmapsto\tt{{(H)}^{2}={(B)}^{2}+{(P)}^{2}}$

$\longmapsto\tt{{(15)}^{2}={(B)}^{2}+{(12)}^{2}}$

$\longmapsto\tt{225-144={(B)}^{2}}$

$\longmapsto\tt{\sqrt{81}=B}$

$\longmapsto\tt\bf{9\:cm=B}$

So , The Length of BC is 9 cm .

Option A) 9 cm is Correct .