Sine of the angle = opposite side over the hypotenuse
sin(42°) = 6.5/h rearrange, solve for h h = 6.5/sin(42°) h = 9.7 cm
For the other triangle, the angle is unknown. I'd split it into two right triangles; down angle x since it is an isosceles it will be bisected into two equivalent triangles.
The hypotenuse we just found is now split in half. 9.7/2 = 4.9 base of the new smaller right triangle.
The new hypotenuse of the smaller triangle is 7.4 cm
Then you have..
sin(x/2) = 4.9/7.4 sin(x/2) = 0.67 use inverse sine function arcSin(0.67) = x/2 41 = x/2 82° = x
There are many ways to solve this problem. This is just what I thought of first using trig.
When construction workers need measurements that are fractions they need to be able to multiply/add/subtract/divide all of those different fractions and mixed numbers.
