Question

macy is trying to construct an isosceles triangle. She assigns and angle measurement of 40 degrees to the unique angle of the triangle. She wants the length fo the opposite side (the base) to be 6 centimeters. How many isosceles triangles can macy construct using this information? A. 3 cm B. 10 centimeters, C. 12 Centimeters D. 14 centimeters, E. 18 centimeters

Answer 1

Given that Macy wants to construct an isosceles triangle, with the unique angle being 40° it implies that for the triangle to be isosceles, the base angles should be the same. The size of the base angles will be:
(180-40)/2=70
given that that the base is 6 cm, Macy can only form 1 triangle with these dimensions.
The length of the other sides will be found using sine rule
a/sin A=b/sin B
a=6 cm
A=40°
b=?
B=70
hence:
6/sin 40=b/sin 70
b=(6sin 70)/sin40
b=8.77 cm