Answer:
57.1
Step-by-step explanation:
Using cosine rule
Cos¤ = 21/25
Cos¤ = 0.84
¤ = 57.12 appropriately 57.1
It’s A, cuz the 4*2 equals 8
Perimeter: all the sides added together, so that would be 1/2+1/2+3/4+3/4, which is 2 and a half feet
Area: the two side lengths multiplied, so 1/2*3/4, which is 3/8 feet squared
Double-angle formulas:
2sinФcosФ=sin(2Ф) /:2
sinФcosФ=1/2*sin(2Ф)
sin(Ф/6)cos(Ф/6)=1/2*sin(2*Ф/6)=1/2*sin(Ф/3)
cos²Ф-sin²Ф=cos(2Ф)/*7
7cos²Ф-7sin²Ф=7cos(2Ф)
7cos²(Ф/9)-7sin²(Ф/9)=7cos(2*Ф/9)=7cos(2Ф/9)
When two triangles are congruent, everything in them is congruent (same). So, the angle bisector of one triangle is congruent to the corresponding angle bisector of the other triangle.
