Question

In the following figure, determine the length of BC. ​

Answer 1

GIVEN :-

• DC = 4 cm.
• Diagonal , AC = 5 cm.

TO FIND :-

• The length of BC.

SOLUTION :-

→ DC = AB = 4 cm. [ opposite side of rectangle are equal ]

• Now we are formed with a right angled triangle , ABC From right angled triangle , ABC we have,

→ hypotenuse , AC = 5 cm.

→ Base , AB = 4 cm.

→ perpendicular , BC = ?.

• Now to find the perpendicular of right angled triangle , ABC we will use the '' Pythagoras theorem '' . Pythagoras theorem says that :- Hypotenuse² = Base² + Perpendicular².

★ BY PYTHAGORAS THEOREM IN ⊿ ABC, ★

→ (AC)² = (AB)² + (BC)²

→ (5)² = (4)² + (BC)²

→ 25 = 16 + (BC)²

→ (BC)² = 25 - 16

→ (BC)² = 9

→ BC = √9

→ BC = 3 cm.

Hence the length of perpendicular , BC of right angled triangle , ABC is 3 cm.

Answer 2

Answer:

3 cm

Step-by-step explanation:

AB=DC

DA=CB

AB= 4cm

AC= 5 cm

By applying Pythagoras theorem

(H)2 = (P)2+(B)2

(AC)2 = (BC)2+ ( AB)2

(5)2=(BC)2+(4)2

25=(BC)2+16

25-16=(BC)2

9=(BC)2

√9=(BC)2

3=BC

Hence answer is 3cm

I hope u will understand.