Draw a triangle ABC with side BC = 7 cm, ∠ B = 45°, ∠ A = 105°. Then, construct a triangle whose sides are times the corresponding sides of Δ ABC.
Steps of construction:
i. Now in order to make a triangle, draw a line segment BC = 7 cm.
ii. Now, construct an angle of 45o at point B and 30o at point C (because 45 + 30 + 105 = 180).
iii. Then, join the lines from points B and C to point A.
This gives us the required triangle ABC.
iv. Dividing the Base, construct a ray BX forming an acute angle from point B.
v. Plot 4 points on BX such that:
BB1 = B1B2 = B2B3 = B3B4.
vi. Join B3 to C.
vii. Now, draw a line from B4 parallel to B3C such that it meets line BC at C’.
viii. Draw A’C’ || AC.
Triangle A’BC’ is the required triangle.