Question

Case Study based-1: Safety Board

A group of students to volunteer are working in making a safety board for school. They

prepared once triangular safety board for their school with title "School Ahead" and "Drive

Slow" in two parts of the triangular board as shown in below figure.


(a) If AD = 2 cm, BD = 5 cm and AE = 3 cm, then EC = ?

(i) 15
/3

(ii) 3/5



(iii) 1/5



(iv) 6/5



(b) If AD = 3 cm, Ab = 9 cm, BC = 6 cm, then DE = ?

(i) 4 cm (ii) 3 cm (iii) 1 cm (iv) 2 cm

(c) If ∠A = 60⁰ and ∠ADE = 50⁰, then ∠C = ?

(i) 70⁰ (ii) 75⁰ (iii) 85⁰ (iv) 40⁰

(d) Which of the following is correct?

(i) ∆ADE ~ ∆ABC (ii) ∆ADE ≅ ∆ABC (iii) Both (i) and (ii) (iv) none of these

(e) What is the ratio of ar(∆ADE) to ar(∆ABC)?

(i) AD²/AB² (ii) AD/AB (iii) 1 (iv) none of these​

Answer 1

Answer:

Step-by-step explanation:

(a) If AD = 2 cm, BD = 5 cm and AE = 3 cm, then EC = ?

When two lines are parallel, then they cut proportionately

AD/ BD = AE/EC

2/ 5 = 3/EC

2 EC= 15

EC= 15/2

(b) If AD = 3 cm, Ab = 9 cm, BC = 6 cm, then DE = ?

(c) If ∠A = 60⁰ and ∠ADE = 50⁰, then ∠C = ?

= If ∠A = 60

∠ADE = 50⁰

∠ABC = 50⁰,(CO INTERIOR ANGLES)

then ∠C = 180 - ( 60+50)

= 180 - 110

= 70

Answer 2

ANSWER:

# (a) (i) 15/2

# (b) (ii) 3 cm Bpt Theorem

# (c) (i) 70 degree

# (d) (i) Tr ADE is similar to Tr ABC

# (e) Not sure

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