MATH 110 HW6
Show all work and justify your answers. Unless the question is trivial, no
credit will be given for answers only.
1. Determine if a triangle with the following sides is a right triangle or
not:
(a) 7, 8, √15.
(b) 4, 8, 9.
2. Consider an equalateral traiangle where each side has length 4 centime-
ters.
(a) What is the height of this triangle?
Hint: use the Pythagorean theorem.
(b) What is the area of this triangle?
3. Prove that the area of an obtuse triangle is 1
2ah where ais the length of
the base and his the height. You may use the fact that a right triangle
has area 1
2ah.
4. Prove that the area of a trapezoid is 1
2h(a+b) where aand bare the
lengths of the two parallel segments and his the distance between them
(i.e his the height of the trapezoid).
5. Suppose a circle has an area of 36π.
(a) What is the radius?
(b) What is the circumference? Leave your answer as a multiple of π.
(c) What is the arclength corresponding to an angle of 100◦? Round
your answer to nearest hundredth.
1
