If you draw a diagonal from upper left to lower right, you divide the figure into two triangles. One is a 3-4-5 right triangle (with area = (1/2)*3*4 = 6). The other is a 5-5-4 isosceles triangle.
The altitude of the isosceles triangle (upper left vertex to side 4) can be found from the Pythagorean theorem as
.. altitude = √(5^2 -2^2) = √21
So, the area of the isosceles triangle is
.. (1/2)*4*√21 = 2√21
The sum of the areas of the two triangles matches selection C.
Twice the area of the triangles, triple that of the rectangles.
2t * 3r = a
Answer:
C
Step-by-step explanation:
(A) Either of
• rotation 180° about point B
• reflection across point B
(B) If the transformation is rigid, the corresponding sides and angles are congruent.
(C) The sequence of letters tells you the correspondence.
AB ⇔ DB
AC ⇔ DE
BC ⇔ BE
∠A ⇔ ∠D
∠ABC ⇔ ∠DBE
∠C ⇔ ∠E
Answer:
Step-by-step explanation:
Use the Law of Cosines
A = arccos[(10²+14²-9.6²)/(2×10×14) ≅ 43.3°
