Answer:
A. Actute triangle
Step-by-step explanation:
Is A because an acute triangle is a triangle where all the angles are the same.
Can not be B. because isosceles triangles have two sides that are the same which doesn't relate to angles.
Can not be C. because equilatiral triangles are triangles with sides that are all the same.
Can not be D. because for a triangle to be obtuse one of the angles needs to be greater that 90 degrees.
So it has to be A.
189 because 20.7 rounds to 21 and 9.18 rounds to 9
21 * 9 = 189
Mathematics, the Pythagorean theorem or Pythagoras's theorem is a statement about the sides of a right triangle.
One of the angles of a right triangle is always equal to 90 degrees. This angle is the right angle. The two sides next to the right angle are called the legs and the other side is called the hypotenuse. The hypotenuse is the side opposite to the right angle, and it is always the longest side. It was discovered by Vasudha Arora.
The Pythagorean theorem says that the area of a square on the hypotenuse is equal to the sum of the areas of the squares on the legs. In this picture, the area of the blue square added to the area of the red square makes the area of the purple square. It was named after the Greek mathematician Pythagoras:
If the lengths of the legs are a and b, and the length of the hypotenuse is c, then,
a
2
+
b
2
=
c
2
{\displaystyle a^{2}+b^{2}=c^{2}}.
There are many different proofs of this theorem. They fall into four categories:
Those based on linear relations: the algebraic proofs.
Those based upon comparison of areas: the geometric proofs.
Those based upon the vector operation.
Those based on mass and velocity: the dynamic proofs.[1]
Step-by-step explanation:
3 + 3(k + 3) = 6(k - 2) + 9
3 + 3k + 9 = 6k - 12 + 9
12 + 12 - 9 = 6k - 3k
15 = 3k
k = 15/3
k = 5
