Answer: C. 84
Step-by-step explanation:
In triangles ABD y BCD:
- AD=CD
- Angle BAD = angle BCD
- BD common side
THEN the triangles are equal because they have two sides and the angle opposite the longest side respectively equal.
CBD = ABD = 42 because the triangles ABD y BCD are equal
ABC = CBD+ABD = 42+42= 84
Answer: option c.
Step-by-step explanation:
You need to remember the identity:
The inverse of the tangent function is arctangent. You need to use this to calculate the angle "R":
You know that you need to find the measure of "R" and 
(which is the opposite side) and 
(which is the adjacent side), you can sustitute values into
Then, you get:
Answer:
then she only has eight pencils in the bag.
Step-by-step explanation:
Answer:
CE= 9cm, DE= 5cm, CD= 10.2956cm
Step-by-step explanation:
Let E be the point of the other triangle.
Using Pythagoras' Theorem,
CD= square root symbol (CE^2 + DE^2)
= square root symbol (9^2+5^2)
= 10.2956cm (6 sf)
