Question

Construct a triangle DEF where DE = 5 cm , Angle D = 69 degree and Angle E = 75 degree

Answer 1

Answer:

The construction is pictured below verify it.

Steps for construction:-

both the D and F angles are similar because DE=EF, so you can say that angle D= angle F

now as everyone knows the sum of three angles is 180 degrees, so....

angle D +angle E + angle F=180

[you can put angle D in place of angle F because both are similar]

so,  angle D +angle D+ angle F =180

2*angleD+30=180

2*angleD=180-30

2*angleD=150

angleD=150/2=75

so, here we have got the value of angleD which is 75 degrees.

ok, here's what you want.

firstly, construct De=5cm.

2.the construct ∠E which is 30 degrees.

3.and finally make an arc on EF↔ with the measurement of 5 cms.

3.then construct DF which will be of 5 cms exactly.

4.m∠D=75